Dimethyl Fumarate and Vaccination Regimens

ABSTRACT

Provided herein is a method of treating or preventing a disease or disorder (e.g., MS) in a subject in need thereof, comprising (a) administering to the subject a first dose of a pharmaceutical composition comprising a fumarate agent (e.g., DMF) for a first dosing period; (b) administering a vaccine; and (c) administering to the subject a second dose of the pharmaceutical composition for a second dosing period.

This application claims the benefit of U.S. provisional application No. 61/953,259 filed Mar. 14, 2014, which is incorporated by reference herein in its entirety.

1. FIELD OF INVENTION

The present invention generally relates to methods of treating or preventing a neurological disease or disorder (e.g., multiple sclerosis) in a subject who receives a vaccine.

2. BACKGROUND OF THE INVENTION

TECFIDERA™ has been approved by the U.S. Food and Drug Administration for the treatment of patients with relapsing forms of multiple sclerosis (MS). TECFIDERA™ contains dimethyl fumarate (DMF), which has the following structure:

The starting dose for TECFIDERA™ is 120 mg twice a day orally. After 7 days, the dose is to be increased to the maintenance dose of 240 mg twice a day orally. TECFIDERA™ can be taken with or without food.

Vaccines are an important class of medications that are frequently used for treating or preventing various diseases, such as infectious diseases. Patients having MS can receive one or more vaccines prior to or during treatments with DMF. One objective of the present invention is to provide a method of treating or preventing multiple sclerosis in patients who receive a vaccine.

3. BRIEF SUMMARY OF THE INVENTION

In some embodiments, the invention provides a method of treating or preventing a disease or disorder (e.g., MS) in a subject in need thereof, comprising

-   -   (a) administering to the subject a first dose of a         pharmaceutical composition for a first dosing period, wherein         the pharmaceutical composition comprises a fumarate agent         selected from the group consisting of monomethyl fumarate         (“MMF”), a compound that metabolizes into monomethyl fumarate in         vivo, a deuterated analog thereof, a pharmaceutically acceptable         salt thereof, and a combination thereof;     -   (b) administering a vaccine to the subject; and     -   (c) administering to the subject a second dose of the         pharmaceutical composition for a second dosing period, wherein         the second dosing period is after the first dosing period,         stopping administration of the pharmaceutical composition (i.e.,         the second dose can be null). In some embodiments, the subject         is administered the same amount of fumarate agent as in the         first dosing period after the second dosing period.

In some embodiments, the invention provides a method of treating or preventing a disease or disorder (e.g., MS) in a subject in need thereof, comprising

-   -   (a) administering to the subject a first dose of a         pharmaceutical composition for a first dosing period, wherein         the pharmaceutical composition comprises a fumarate agent         selected from the group consisting of monomethyl fumarate, a         compound that metabolizes into monomethyl fumarate in vivo, a         deuterated analog thereof, a pharmaceutically acceptable salt         thereof, and a combination thereof, and wherein the subject         receives a vaccine;     -   (b) determining an immune response of the subject to the vaccine         before the end of the first dosing period; and     -   (c) adjusting the first dose to a second dose of the         pharmaceutical composition, which includes stopping         administration of the pharmaceutical composition (i.e., the         second dose can be null), based on the immune response         determined in step (b).

In some embodiments, the invention provides a method of treating or preventing a disease or disorder (e.g., MS) in a subject in need thereof, comprising

-   -   (a) administering to the subject a first dose of a         pharmaceutical composition for a first dosing period, wherein         the pharmaceutical composition comprises a fumarate agent         selected from the group consisting of monomethyl fumarate, a         compound that metabolizes into monomethyl fumarate in vivo, a         deuterated analog thereof, a pharmaceutically acceptable salt         thereof, and a combination thereof, and wherein the subject         receives a vaccine;     -   (b) determining an immune response of the subject to the vaccine         before the end of the first dosing period; and     -   (c) administering to the subject a second dose of the         pharmaceutical composition for a second dosing period. In some         embodiments, the second dose is equal to or less than the first         dose.

In some embodiments, the subject is administered the same amount of fumarate agent as in the first dosing period after the second dosing period.

In some embodiments, the first or second dose of the pharmaceutical composition contains a therapeutically effective amount of the fumarate agent. In some embodiments, the fumarate agent comprises MMF, DMF, or a combination thereof. In some embodiments, the fumarate agent comprises DMF. In some embodiments, the only active ingredient in the pharmaceutical composition is DMF. In some embodiments, the first dose is a daily amount of about 480 mg dimethyl fumarate administered twice per day (BID). In some embodiments, the second dose is about 0 mg to about 480 mg fumarate agent (e.g., DMF).

In some embodiments, the step of determining the immune response comprises obtaining serum antibody (e.g., IgG or IgM) levels in the subject induced by the vaccine post-immunization (e.g., 4 weeks after immunization), obtaining the serum antibody (e.g., IgG or IgM) levels in the subject pre-immunization, and comparing the serum antibody levels in the subject pre- and post-immunization. In some embodiments, the serum antibody is IgG against tetanus diphtheria toxoids, keyhole limpet hemocyanin, or pneumovax-23, and the serum IgG level in the subject increases less than 4-fold (e.g., less than 3-fold or less than 2-fold) from pre-vaccination to 4 weeks after vaccination. In some embodiments, the serum IgG level in the subject increases at least 2-fold (e.g., at least 4-fold or at least 10-fold) from pre-immunization to 4 weeks after immunization.

The immune response following vaccination, e.g., as determined by the determining step, can affect the second dose. In some embodiments, the immune response of the subject to the vaccine is characterized in that the serum antibody level induced by the vaccine in the subject increases less than 4-fold (e.g., less than 3-fold or less than 2-fold) from pre-vaccination to 4 weeks after vaccination, and the second dose is about 5% to about 95% (e.g., about 10%, about 20%, about 30%, about 40%, about 50%, about 60%, about 70%, about 80%, about 90%, or any ranges thereof) of the first dose. In some embodiments, the second dose is a daily dose of about 0 to about 480 mg. In some embodiments, the immune response of the subject to the vaccine is characterized in that the serum antibody level in the subject increases at least 2-fold (e.g., at least 4-fold or at least 10-fold) from pre-immunization to 4 weeks after immunization, and the second dose is the same as the first dose.

In some embodiments, the methods described herein further comprise administering a titration dose of the pharmaceutical composition prior to the first and/or second dosing periods. In some embodiments, the titration dose is administered to the subject for at least 7 days prior to beginning the first and/or second dosing period. In some embodiments, the fumarate agent is DMF and the titration dose is a daily dose of about 240 mg DMF administered BID for 7 consecutive days. In some embodiments, the fumarate agent is DMF and the titration dose is a daily dose of 360 mg DMF administered three times a day.

In some embodiments, the invention also provides a method of treating or preventing a disease or disorder (e.g., MS) in a subject who receives a vaccine, comprising screening a plurality of doses of a pharmaceutical composition comprising a fumarate agent selected from the group consisting of monomethyl fumarate, a compound that metabolizes into monomethyl fumarate in vivo, a deuterated analog thereof, a pharmaceutically acceptable salt thereof, and a combination thereof, by

-   -   (1) identifying a first group of subjects and at least a second         group of subjects, wherein both the first and second groups of         subjects receive a vaccine, wherein the first group of subjects         is treated with a first dose of the pharmaceutical composition,         and the second group of subjects is treated with a second dose         of the pharmaceutical composition; and     -   (2) determining a lower risk dose. In some embodiments, the         method further comprises administering the lower risk dose of         the pharmaceutical composition to the subject. In some         embodiments, the lower risk dose is determined by comparing         immune responses to the vaccine between the first and second         groups of subjects.

In some embodiments, the invention provides a method of treating or preventing multiple sclerosis in a subject in need thereof, comprising

-   -   (a) determining a subject's baseline lymphocyte count prior to         treatment;     -   (b) administering to the subject a first dose of a         pharmaceutical composition for a first dosing period, wherein         the pharmaceutical composition comprises a fumarate agent         selected from the group consisting of monomethyl fumarate, a         compound that metabolizes into monomethyl fumarate in vivo, a         deuterated analog thereof, a pharmaceutically acceptable salt         thereof, and a combination thereof,     -   (c) determining a subject's total lymphocyte count after the         first dosing period; and     -   (d) if the lymphocyte count after the first dosing period is         about 90% of the baseline lymphocyte count or lower, do not         administer tetanus diphtheria toxoids vaccine, keyhole limpet         hemocyanin vaccine, pneumovax-23 vaccine, or any combinations         thereof.

In some embodiments, the invention provides a method of treating multiple sclerosis in a human subject in need thereof comprising

-   -   (a) administering a therapeutically effective amount of dimethyl         fumarate to the subject; and     -   (b) administering a vaccine to the subject.

4. DETAILED DESCRIPTION OF THE INVENTION 4.1 Definitions

As used herein, “a” or “an” means one or more unless otherwise specified.

Unless specifically stated or obvious from context, as used herein, the term “about” is understood as within a range of normal tolerance in the art, for example, within 20% of the stated value. As used herein, “about” a specific value also includes the specific value, for example, about 10% includes 10%.

As used herein, the term “DMF,” or “BG00012” refers to the compound dimethyl fumarate. The term “MMF” refers to the compound, or an ionized form of, monomethyl fumarate.

Open terms such as “include,” “including,” “contain,” “containing” and the like mean “comprising.”

The term “treating” refers to administering a therapy in an amount, manner, or mode effective to improve a condition, symptom, or parameter associated with a disease or disorder.

The term “prophylaxis”, the term “prophylactic treatment”, or “preventing” refers to precluding a patient from getting a disorder, causing a patient to remain free of a disorder for a longer period of time, or halting the progression of a disorder, to either a statistically significant degree or to a degree detectable to one skilled in the art.

The terms “therapeutically effective dose” and “therapeutically effective amount” refer to that amount of a compound which results in prevention or delay of onset or amelioration of symptoms of a neurological disorder in a subject or an attainment of a desired biological outcome, such as reduced neurodegeneration (e.g., demyelination, axonal loss, or neuronal death) or slowing in the accumulation of physical disability (e.g., as indicated by, e.g., a reduced rate of worsening of a clinical score (e.g., Enhanced Disability Status Scale (“EDSS”)) or another suitable parameter indicating disease state. Exemplary disease state parameters include the number of clinical relapses, number of T1 lesions, reduced mean number of new and total gadolinium-enhancing (Gd+) lesions on brain MRI scans, number and volume of new or newly-enlarging T2 hyperintense lesions, number of new T1 hypointense lesions, percentage of Gd+ lesions that convert to T1 hypointense lesions, measures of atrophy and magnetization transfer ratio, and the like).

The term “microtablet” means a compact in the form of a small (micro) tablet having a mean diameter of less than 5,000 microns (e.g., about 1,000 microns to about 3,000 microns), excluding any coating, that comprises the active ingredient(s) and one or more excipients. The active ingredient(s) and excipients can be homogeneously or heterogeneously mixed in the microtablet. In any of the embodiments described herein, the microtablets may be coated, for example, by a seal coating, an enteric coating, or a combination thereof.

As used herein, when an object (e.g., a microtablet) is said to be “coated” or have a “coating,” it is to be understood that the object can be fully or partially coated by one or more coatings. Similarly, when an object (e.g., a microtablet) is said to be “encapsulated,” it is to be understood that the object can be fully or partially encapsulated.

The term “subject” as used herein generally refers to human, including healthy human or a patient with certain diseases or disorders (e.g., MS).

4.2 Compounds that can be Metabolized into MMF

A compound that can be metabolized into MMF in vivo, as used herein, includes DMF. A compound that can be metabolized into MMF in vivo, as used herein, includes any such compound known in the art. For example, a compound that can be metabolized into MMF in vivo, as used herein includes, for example, any compound described in U.S. application Ser. No. 13/760,916, the content of which is incorporated herein by reference in its entirety.

Compounds that can be metabolized into MMF in vivo include compounds of Formula I:

-   -   or a pharmaceutically acceptable salt thereof, wherein     -   R¹ and R² are independently chosen from hydrogen, C₁₋₆ alkyl,         and substituted C₁₋₆ alkyl;     -   R³ and R⁴ are independently chosen from hydrogen, C₁₋₆ alkyl,         substituted C₁₋₆ alkyl, C₁₋₆ heteroalkyl, substituted C₁₋₆         heteroalkyl, C₄₋₁₂ cycloalkylalkyl, substituted C₄₋₁₂         cycloalkylalkyl, C₇₋₁₂ arylalkyl, and substituted C₇₋₁₂         arylalkyl; or R³ and R⁴ together with the nitrogen to which they         are bonded form a ring chosen from a C₅₋₁₀ heteroaryl,         substituted C₅₋₁₀ heteroaryl, C₅₋₁₀ heterocycloalkyl, and         substituted C₅₋₁₀ heterocycloalkyl; and     -   R⁵ is chosen from methyl, ethyl, and C₃₋₆ alkyl;     -   wherein each substituent group is independently chosen from         halogen, —OH, —CN, —CF₃, ═O, —NO₂, benzyl, —C(O)NR¹¹ ₂, —R¹¹,         —OR¹¹, —C(O)R¹¹, —COOR¹¹, and —NR¹¹ ₂ wherein each R¹¹ is         independently chosen from hydrogen and C₁₋₄ alkyl; with the         proviso that when R⁵ is ethyl; then R³ and R⁴ are independently         chosen from hydrogen, C₁₋₆ alkyl, and substituted C₁₋₆ alkyl.

Useful examples of a compound of Formula (I) include: (N,N-diethylcarbamoyl)methyl methyl(2E)b3ut-2-ene-1,4-dioate; methyl[N-benzylcarbamoyl]methyl(2E)but-2-ene-1,4-dioate; methyl 2-morpholin-4-yl-2-oxoethyl(2E)but-2-ene-1,4-dioate; (N-butylcarbamoyl)methyl methyl(2E)but-2-ene-1,4-dioate; [N-(2-methoxyethyl)carbamoyl]methyl methyl(2E)but-2-ene-1,4-dioate; 2-{2-[(2E)-3-(methoxycarbonyl)prop-2-enoyloxy]acetylamino}acetic acid;

-   4-{2-[(2E)-3-(methoxycarbonyl)prop-2-enoyloxy]acetylamino}butanoic     acid;     methyl(N-(1,3,4-thiadiazol-2-yl)carbamoyl)methyl(2E)but-2ene-1,4-dioate; -   (N,N-dimethylcarbamoyl)methyl methyl(2E)but-2-ene-1,4-dioate; -   (N-methoxy-N-methylcarbamoyl)methyl methyl(2E)but-2-ene-1,4-dioate; -   bis-(2-methoxyethylamino)carbamoyl]methyl     methyl(2E)but-2-ene-1,4-dioate; -   [N-(methoxycarbonyl)carbamoyl]methyl methyl(2E)but-2ene-1,4-dioate;     4-{2-[(2E)-3-(methoxycarbonyl)prop-2-enoyloxy]acetylamino}butanoic     acid, sodium salt; methyl     2-oxo-2-piperazinylethyl(2E)but-2-ene-1,4-dioate; methyl     2-oxo-2-(2-oxo(1,3-oxazolidin-3-yl)ethyl(2E)but-2ene-1,4-dioate; -   {N-[2-(dimethylamino)ethyl]carbamoyl}methyl methyl(2E)but-2ene-1,4     dioate; methyl     2-(4-methylpiperazinyl)-2-oxoethyl(2E)but-2-ene-1,4-dioate; methyl     {N-[(propylamino)carbonyl]carbamoyl}methyl(2E)but-2ene-1,4-dioate; -   2-(4-acetylpiperazinyl)-2-oxoethyl methyl(2E)but-2ene-1,4-dioate;     {N,N-bis[2-(methylethoxy)ethyl]carbamoyl}methyl     methyl(2E)but-2-ene-1,4-dioate; methyl     2-(4-benzylpiperazinyl)-2-oxoethyl(2E)but-2-ene-1,4-dioate;     [N,N-bis(2-ethoxyethyl)carbamoyl]methyl     methyl(2E)but-2-ene-1,4-dioate;     2-{(2S)-2-[(tert-butyl)oxycarbonyl]pyrrolidinyl}-2-oxoethyl     methyl(2E)but-2ene-1,4-dioate; -   1-{2-{(2E)-3-(methoxycarbonyl)prop-2-enoyloxy]acetyl}(2S)pyrrolidine-2-carboxylic     acid; (N-{[tert-butyl)oxycarbonyl]methyl}-N-methylcarbamoyl)methyl     methyl(2E)but-2ene-1,4-dioate; -   {N-(ethoxycarbonyl)methyl]-N-methylcarbamoyl}methyl     methyl(2E)but-2-ene-1,4-dioate; -   methyl 1-methyl-2-morpholin-4-yl-2-oxoethyl(2E)but-2-ene-1,4-dioate; -   [N,N-bis(2-methoxyethyl)carbamoyl]ethyl     methyl(2E)but-2-ene-1,4-dioate; -   (N,N-dimethylcarbamoyl)ethyl methyl(2E)but-2-ene-1,4-dioate;     2-{2-[(2E)-3-(methoxy     carbonyl)prop-2-enoyloxyl]-N-methylacetylamino}acetic acid;     (N-{[(tert-butyl)oxycarbonyl]methyl}carbamoyl)methyl     methyl(2E)but-2-ene-1,4-dioate;     (2E)but-methyl-N-{[(methylethyl)oxycarbonyl]methyl}carbamoyl)methyl(2E)but-2-ene-1,4-dioate;     {N-[(ethoxycarbonyl)methyl]-N-benzylcarbamoyl}methyl     methyl(2E)but-2-ene-1,4-dioate;     {N-[(ethoxycarbonyl)methyl]-N-benzylcarbamoyl}ethyl     methyl(2E)but-2-ene-1,4-dioate; -   {N-[(ethoxycarbonyl)methyl]-N-methylcarbamoyl}ethyl     methyl(2E)but-2-ene-1,4-dioate; (1S)-1-methyl-2-morpholin-4-yl-2-oxo     ethyl methyl(2E)but-2-ene-1,4-dioate;     (1S)-1-[N,N-bis(2-methoxyethyl)carbamoyl]ethyl     methyl(2E)but-2-ene-1,4-dioate; (1R)-1-(N,N-diethylcarbamoyl)ethyl     methyl(2E)but-2-ene-1,4-dioate; and a pharmaceutically acceptable     salt of any of the foregoing.

Useful examples of a compound of Formula (I) also include: (N,N-diethylcarbamoyl)methyl methyl(2E)but-2-ene-1,4-dioate; methyl[N-benzylcarbamoyl]methyl(2E)but-2-ene-1,4-dioate; methyl 2-morpholin-4-yl-2-oxoethyl(2E)but-2-ene-1,4-dioate; (N-butylcarbamoyl)methyl methyl(2E)but-2-ene-1,4-dioate; [N-(2-methoxyethyl)carbamoyl]methyl methyl(2E)but-2-ene-1,4-dioate; 2-{2-[(2E)-3-(methoxycarbonyl)prop-2-enoyloxy]acetylamino}acetic acid;

-   {2-[(2E)-3-(methoxycarbonyl)prop-2-enoyloxy]acetylamino}butanoic     acid;     methyl(N-(1,3,4-thiadiazol-2-yl)carbamoyl)methyl(2E)but-2ene-1,4-dioate;     (N,N-dimethylcarbamoyl)methyl methyl(2E)but-2-ene-1,4-dioate;     (N-methoxy-N-methylcarbamoyl)methyl methyl(2E)but-2-ene-1,4-dioate; -   bis-(2-methoxyethylamino)carbamoyl]methyl     methyl(2E)but-2-ene-1,4-dioate; -   [N-(methoxycarbonyl)carbamoyl]methyl methyl(2E)but-2ene-1,4-dioate;     methyl 2-oxo-2-piperazinylethyl(2E)but-2-ene-1,4-dioate; methyl     2-oxo-2-(2-oxo(1,3-oxazolidin-3-yl)ethyl(2E)but-2ene-1,4-dioate; -   {N-[2-(dimethylamino)ethyl]carbamoyl}methyl     methyl(2E)but-2ene-1,4-dioate; -   (N-[(methoxycarbonyl)ethyl]carbamoyl)methyl     methyl(2E)but-2-ene-1,4-dioate;     2-{2-[(2E)-3-(methoxycarbonyl)prop-2-enoyloxy]acetylamino}propanoic     acid; and a pharmaceutically acceptable salt of any of the     foregoing.

Compounds that can be metabolized into MMF in vivo also include compounds of Formula II:

-   -   or a pharmaceutically acceptable salt thereof, wherein     -   R⁶ is chosen from C₁₋₆ alkyl, substituted C₁₋₆ alkyl, C₁₋₆         heteroalkyl, substituted C₁₋₆ heteroalkyl, C₃₋₈ cycloalkyl,         substituted C₃₋₈ cycloalkyl, C₆₋₈ aryl, substituted C₆₋₈ aryl,         and —OR¹⁰ wherein R¹⁰ is chosen from C₁₋₆ alkyl, substituted         C₁₋₆ alkyl, C₃₋₁₀ cycloalkyl, substituted C₃₋₁₀ cycloalkyl,         C₆₋₁₀ aryl, and substituted C₆₋₁₀ aryl;     -   R⁷ and R⁸ are independently chosen from hydrogen, C₁₋₆ alkyl,         and substituted C₁₋₆ alkyl; and     -   R⁹ is chosen from C₁₋₆ alkyl and substituted C₁₋₆ alkyl;     -   wherein each substituent group is independently chosen from         halogen, —OH, —CN, —CF₃, ═O, —NO₂, benzyl, —C(O)NR¹¹ ₂, —R¹¹,         —OR¹¹, —C(O)R¹¹, —COOR¹¹, and —NR¹¹ ₂ wherein each R¹¹ is         independently chosen from hydrogen and C₁₋₄ alkyl.

Useful examples of a compound of Formula (II) include: ethoxycarbonyloxyethyl methyl(2E)but-2-ene-1,4-dioate; methyl(methylethoxycarbonyloxy)ethyl(2E)but-2-ene-1,4-dioate; (cyclohexyloxycarbonyloxy)ethyl methyl(2E)but-2-ene-1,4-dioate; and a pharmaceutically acceptable salt of any of the foregoing.

Additional useful examples of a compound of Formula (II) include: methyl(2-methylpropanoyloxy)ethyl(2E)but-2-ene-1,4-dioate; methyl phenylcarbonyloxyethyl(2E)but-2-ene-1,4-dioate; cyclohexylcarbonyloxybutyl methyl(2E)but-2-ene-1,4-dioate; [(2E)-3-(methoxycarbonyl)prop-2-enoyloxy]ethyl methyl(2E)but-2-ene-1,4-dioate; methyl 2-methyl-1-phenylcarbonyloxypropyl(2E)but-2-ene-1,4-dioate; and a pharmaceutically acceptable salt of any of the foregoing.

Useful examples of a compound of Formula (II) also include:

-   ethoxycarbonyloxyethyl methyl(2E)but-2-ene-1,4-dioate; -   methyl(methylethoxycarbonyloxy)ethyl(2E)but-2-ene-1,4-dioate; -   methyl(2-methylpropanoyloxy)ethyl(2E)but-2-ene-1,4-dioate; -   methyl phenylcarbonyloxyethyl(2E)but-2-ene-1,4-dioate; -   cyclohexylcarbonyloxybutyl methyl(2E)but-2-ene-1,4-dioate;     [(2E)-3-(methoxycarbonyl)prop-2-enoyloxy]ethyl     methyl(2E)but-2-ene-1,4-dioate; (cyclohexyloxycarbonyloxy)ethyl     methyl(2E)but-2-ene-1,4-dioate; methyl     2-methyl-1-phenylcarbonyloxypropyl(2E)but-2-ene-1,4-dioate;     3-({[(2E)-3-(methoxycarbonyl)prop-2-enoyloxy]methyl}oxycarbonyl)(3S)-3-aminopropanoic     acid, 2,2,2-trifluoroacetic acid;     3-({[(2E)-3-(methoxycarbonyl)prop-2-enoyloxy]methyl}oxycarbonyl)(2S)-2-aminopropanoic     acid, 2,2,2-trifluoroacetic acid;     3-({[(2E)-3-(methoxycarbonyl)prop-2-enoyloxy]methyl}oxycarbonyl)(3S)-3-(2-aminoacetylamino)propanoic     acid, 2,2,2-trifluoroacetic acid;     3-({[(2E)-3-(methoxycarbonyl)prop-2-enoyloxy]methyl}oxycarbonyl)(2S)-2-aminopropanoic     acid, 2,2,2-trifluoroacetic acid;     3-{[(2E)-3-(methoxycarbonyl)prop-2enoyloxy]ethoxycarbonyloxy}(2S)-2-aminopropanoic     acid, chloride; and a pharmaceutically acceptable salt of any of the     foregoing.

Compounds that can be metabolized into MMF in vivo also include compounds of Formula (III):

-   -   or a pharmaceutically acceptable salt thereof, wherein:         -   R² is C₁-C₁₀ alkyl, C₅-C₁₅ aryl, hydroxyl, —O—C₁-C₁₀ alkyl,             or —O—C₅-C₁₅ aryl;         -   each of R³, R⁴, and R⁵, independently, is C₁-C₁₀ alkyl,             C₅-C₁₅ aryl, hydroxyl,         -   —O—C₁-C₁₀ alkyl, —O—C₅-C₁₅ aryl, or

-   -   wherein R¹ is C₁-C₂₄ alkyl or C₅-C₅₀ aryl; each of which can be         optionally substituted; and     -   each of m, n, and r, independently, is 0-4;     -   provided that at least one of R³, R⁴, and R⁵ is

Useful examples of a compound of formula (III) include (dimethylsilanediyl)dimethyl difumarate; methyl ((trimethoxysilyl)methyl) fumarate; methyl ((trihydroxysilyl)methyl) fumarate; trimethyl (methylsilanetriyl) trifumarate; and a pharmaceutically acceptable salt of any of the foregoing.

Compounds that can be metabolized into MMF in vivo also include compounds of Formula (IV):

-   -   or a pharmaceutically acceptable salt thereof, wherein:     -   each of, independently, R² and R³, is C₁-C₁₀ alkyl or C₅-C₁₅         aryl.     -   R² and R³ can be the same or different, can be optionally         substituted, and independently can be selected from the group         consisting of C₁-C₁₀ alkyl or C₅-C₁₅ aryl.

Compound that can be metabolized into MMF in vivo also include compounds of Formula (V):

-   -   or a pharmaceutically acceptable salt thereof, wherein:     -   R¹ is C₁-C₂₄ alkyl or C₅-C₅₀ aryl;     -   each of R², R³, and R⁵, independently, is hydroxyl, C₁-C₁₀         alkyl, C₅-C₁₅ aryl, —O—C₁-C₁₀ alkyl, or —O—C₅-C₁₅ aryl; and     -   n is 1 or 2.

Additional compounds that can be metabolized into MMF in vivo include compounds of Formula (VI):

-   -   or a pharmaceutically acceptable salt thereof, wherein:     -   R¹ is C₁-C₂₄ alkyl or C₅-C₅₀ aryl; and     -   R² is C₁-C₁₀ alkyl.

As used herein, the term “fumarate agent” refers to MMF, a compound that can be metabolized into MMF in vivo (e.g., DMF), or a pharmaceutically acceptable salt thereof or combinations thereof, or deuterated analogues thereof. In some embodiments, the fumarate agent can include more than one compound, for example, a combination of MMF and DMF. In some embodiments, the fumarate agent is a single compound, e.g., DMF.

Useful examples of deuterated analogs include compounds of formula (VII): a compound of formula (I)

-   -   or a pharmaceutically acceptable salt thereof, wherein     -   each of R¹ and R², independently, is hydrogen, deuterium,         deuterated methyl, deuterated ethyl, C₁₋₆ aliphatic, phenyl, 3-7         membered saturated or partially unsaturated monocyclic         carbocyclic ring, 3-7 membered saturated or partially         unsaturated monocyclic heterocyclic ring having 1-3 heteroatoms         independently selected from nitrogen, oxygen, and sulfur, or a         5-6 membered heteroaryl ring having 1-3 heteroatoms         independently selected from nitrogen, oxygen, and sulfur, and         each of R³ and R⁴, independently, is hydrogen or deuterium,         provided that the compound of formula (VII) contains at least         one deuterium atom and that R¹ and R² are not hydrogen at the         same time.

Useful examples of compounds of formula (VII) include (²H₆)dimethyl fumaric acid ester, (²H₃)methyl fumaric acid ester, (²H₃)dimethyl fumaric acid ester, dimethyl fumaric (2,3-²H₂) acid ester, methyl fumaric (2,3-²H₂) acid ester, ethyl fumaric (2,3-²H₂) acid ester, (²H₃)methyl fumaric (2,3-²H₂) acid ester, (²H₆)dimethyl fumaric (2,3-²H₂) acid ester, methyl (2-morpholino-2-oxoethyl) fumaric (2,3-²H₂) acid ester, methyl (4-morpholino-1-butyl) fumaric (2,3-²H₂) acid ester, 2-(benzoyloxy)ethyl methyl fumaric (2,3-²H₂) acid ester, 2-(benzoyloxy)ethyl (²H₃)methyl fumaric acid ester, (S)-2-((2-amino-3-phenylpropanoyl)oxy)ethyl methyl fumaric (2,3-²H₂) acid ester, or (S)-2-((2-amino-3-phenylpropanoyl)oxy)ethyl (²H₃)methyl fumaric acid ester.

4.3 Method 1. Treating a Subject Who May Receive a Vaccine 4.3.1 Method 1a

In some embodiments, the invention provides a method of treating or preventing a disease or disorder (e.g., MS) in a subject in need thereof, comprising

-   -   (a) administering to the subject a first dose of a         pharmaceutical composition for a first dosing period, wherein         the pharmaceutical composition comprises a fumarate agent         selected from the group consisting of monomethyl fumarate, a         compound that metabolizes into monomethyl fumarate in vivo, a         deuterated analog thereof, a pharmaceutically acceptable salt         thereof, and a combination thereof,     -   (b) administering a vaccine to the subject; and     -   (c) administering to the subject a second dose of the         pharmaceutical composition for a second dosing period, wherein         the second dosing period is after the first dosing period. In         some embodiments, the disease or disorder is MS. In some         embodiments, the second dose is about 0 to about 480 mg fumarate         agent.

4.3.2 Method 1b

In some embodiments, the invention provides a method of treating or preventing a disease or disorder (e.g., MS) in a subject in need thereof, comprising

-   -   (a) administering to the subject a first dose of a         pharmaceutical composition for a first dosing period, wherein         the pharmaceutical composition comprises a fumarate agent         selected from the group consisting of monomethyl fumarate, a         compound that metabolizes into monomethyl fumarate in vivo, a         deuterated analog thereof, a pharmaceutically acceptable salt         thereof, and a combination thereof, and wherein the subject         receives a vaccine;     -   (b) determining an immune response of the subject to the vaccine         before the end of the first dosing period; and     -   (c) adjusting the first dose to a second dose of the         pharmaceutical composition, which includes stopping         administration of the pharmaceutical composition (i.e., the         second dose can be about 0 to about 480 mg fumarate agent),         based on the immune response determined in step (b).

4.3.3 Method 1e

In some embodiments, the invention provides a method of treating or preventing a disease or disorder (e.g., MS) in a subject in need thereof, comprising

-   -   (a) administering to the subject a first dose of a         pharmaceutical composition for a first dosing period, wherein         the pharmaceutical composition comprises a fumarate agent         selected from the group consisting of monomethyl fumarate, a         compound that metabolizes into monomethyl fumarate in vivo, a         deuterated analog thereof, a pharmaceutically acceptable salt         thereof, and a combination thereof, and wherein the subject         receives a vaccine;     -   (b) determining an immune response of the subject to the vaccine         before the end of the first dosing period; and     -   (c) administering to the subject a second dose of the         pharmaceutical composition for a second dosing period. In some         embodiments, the second dose is equal to or less than the first         dose.

4.3.4 Method 1d

In some embodiments, the invention provides a method of treating or preventing multiple sclerosis in a subject in need thereof, comprising

-   -   (a) determining a subject's baseline lymphocyte count prior to         treatment;     -   (b) administering to the subject a first dose of a         pharmaceutical composition for a first dosing period, wherein         the pharmaceutical composition comprises a fumarate agent         selected from the group consisting of monomethyl fumarate, a         compound that metabolizes into monomethyl fumarate in vivo, a         deuterated analog thereof, a pharmaceutically acceptable salt         thereof, and a combination thereof;     -   (c) determining a subject's total lymphocyte count after the         first dosing period; and     -   (d) if the lymphocyte count after the first dosing period is 90%         of the baseline lymphocyte count or lower, do not administer         tetanus diphtheria toxoids vaccine, keyhole limpet hemocyanin         vaccine, pneumovax-23 vaccine, or any combinations thereof.

4.3.5 Method 1e

In some embodiments, the invention provides a method of treating multiple sclerosis in a human subject in need thereof comprising

-   -   (a) administering a therapeutically effective amount of dimethyl         fumarate to the subject; and     -   (b) administering a vaccine to the subject.

In one embodiment, the therapeutically effective amount of dimethyl fumarate is a maintenance dose that is repeatedly administered over at least a period of time, and said step (b) of administering said vaccine is during said period of time.

The period of time can be, for example, for at least one, two, three, four, five, six, or seven days, or for at least one, two, three, or four weeks, or for at least one, two, three, four, five, six, seven, eight, nine, ten, eleven, twelve months, or longer. In one embodiment, the period of time is 1 week. In another embodiment, the period of time is 6 months. In a specific embodiment, the maintenance dose is administered after a time period during which the administered dosage is lower than the maintenance dose. For example, administration of a maintenance dose of 240 mg dimethyl fumarate administered orally twice daily can be immediately preceded by a time period of uptitration consisting of orally administered 120 mg dimethyl fumarate twice daily for 7 days. As another example, administration of a maintenance dose of 240 mg dimethyl fumarate administered orally twice daily can be immediately preceded by a time period of uptitration consisting of orally administering a starting dose of 120 mg dimethyl fumarate daily for 2 weeks, followed by 120 mg dimethyl fumarate twice daily for 2 weeks, followed by 360 mg dimethyl fumarate daily for 2 weeks; wherein the 360 mg dimethyl fumarate daily is 240 mg dimethyl fumarate in the morning and 120 mg dimethyl fumarate in the evening.

In one embodiment, the maintenance dose is orally administered 480 mg dimethyl fumarate daily. In a specific embodiment, the maintenance dose is orally administered 240 mg dimethyl fumarate twice daily.

In one embodiment, the immune response to said vaccine is decreased in said subject relative to the immune response in the absence of said step (a) of administering a therapeutically effective amount of dimethyl fumarate.

In one embodiment, the multiple sclerosis is a relapsing form of multiple sclerosis.

In one embodiment, the multiple sclerosis is relapsing-remitting multiple sclerosis

4.3.6 Diseases and Disorders

Suitable diseases and disorders that can be treated by the fumarate agent are known in the art, which include any diseases or disorders where administering DMF is helpful.

In some embodiments, the disease or disorder where administering DMF is helpful is

-   -   (1) an autoimmune disease selected from the group consisting of         polyarthritis, rheumatoid arthritis, multiple sclerosis,         graft-versus-host reactions, juvenile-onset diabetes,         Hashimoto's thyroiditis, Grave's disease, systemic Lupus         crythematodes (SLE), Sjogren's syndrome, pernicious anaemia and         chronic active (=lupoid) hepatitis, psoriasis, psoriatic         arthritis, neurodermatitis and enteritis regionalis Crohn;     -   (2) a mitochondrial disease selected from the group consisting         of Parkinson syndrome, Alzheimer's disease, Chorea Huntington         disease, retinopathia pigmentosa or forms of mitochondrial         encephalomyopathy;     -   (3) a NF-kappaB mediated diseases selected from the group         consisting of progressive systemic sclerodermia, osteochondritis         syphilitica (Wegener's disease), cutis marmorata (livedo         reticularis), Behcet disease, panarteriitis, colitis ulcerosa,         vasculitis, osteoarthritis, gout, artenosclerosis, Reiter's         disease, pulmonary granulomatosis, types of encephalitis,         endotoxic shock (septic-toxic shock), sepsis, pneumonia,         encephalomyelitis, anorexia nervosa, hepatitis (acute hepatitis,         chronic hepatitis, toxic hepatitis, alcohol-induced hepatitis,         viral hepatitis, jaundice, liver insufficiency and         cytomegaloviral hepatitis), Rennert T-lymphomatosis, mesangial         nephritis, post-angioplastic restenosis, reperfusion syndrome,         cytomegaloviral retinopathy, adenoviral diseases such as         adenoviral colds, adenoviral pharyngoconjunctival fever and         adenoviral ophthalmia, AIDS, Guillain-Barré syndrome,         post-herpetic or post-zoster neuralgia, inflammatory         demyelinising polyneuropathy, mononeuropathia multiplex,         mucoviscidosis, Bechterew's disease, Barett oesophagus, EBV         (Epstein-Barr virus) infection, cardiac remodeling, interstitial         cystitis, diabetes mellitus type II, human tumour         radiosensitisation, multi-resistance of malignant cells to         chemotherapeutic agents (multidrug resistance in chemotherapy),         granuloma annulare and cancers such as mamma carcinoma, colon         carcinoma, melanoma, primary liver cell carcinoma,         adenocarcinoma, kaposi's sarcoma, prostate carcinoma, leukaemia         such as acute mycloid leukaemia, multiple myeloma         (plasmocytoma), Burkitt lymphoma and Castleman tumour;     -   (4) a cardiovascular disease selected from the group consisting         of cardiac insufficiency, myocardial infarct, angina pectoris         and combinations thereof;     -   (5) a respiratory disease selected from the group consisting of         asthma, chronic obstructive pulmonary diseases, PDGF induced         thymidine uptake of bronchial smooth muscle cells, bronchial         smooth muscle cell proliferation, and combinations thereof;     -   (6) a neurodegeneration or neuroinflammation selected from the         group consisting of Adrenal Leukodystrophy (ALD), Alcoholism,         Alexander's disease, Alper's disease, Alzheimer's disease,         Amyotrophic lateral sclerosis (Lou Gehrig's Disease), Ataxia         telangiectasia, Batten disease (also known as         Spielmeyer-Vogt-Sjögren-Batten disease), Bovine spongiform         encephalopathy (BSE), Canavan disease, Cerebral palsy, Cockayne         syndrome, Corticobasal degeneration, Creutzfeldt-Jakob disease,         Familial Fatal Insomnia, Frontotemporal lobar degeneration,         Huntington's disease, HIV-associated dementia, Kennedy's         disease, Krabbe's disease, Lewy body dementia, Neuroborreliosis,         Machado-Joseph disease (Spinocerebellar ataxia type 3), Multiple         System Atrophy, Multiple sclerosis, Narcolepsy, Niemann Pick         disease, Parkinson's disease, Pelizaeus-Merzbacher Disease,         Pick's disease, Primary lateral sclerosis, Prion diseases,         Progressive Supranuclear Palsy, Refsum's disease, Sandhoff         disease, Schilder's disease, Subacute combined degeneration of         spinal cord secondary to Pernicious Anaemia,         Spielmeyer-Vogt-Sjögren-Batten disease (also known as Batten         disease), Spinocerebellar ataxia, Spinal muscular atrophy,         Steele-Richardson-Olszewski disease, Tabes dorsalis, Toxic         encephalopathy, LHON (Leber's Hereditary optic neuropathy),         MELAS (Mitochondrial Encephalomyopathy; Lactic Acidosis;         Stroke), MERRF (Myoclonic Epilepsy; Ragged Red Fibers), PEO         (Progressive External Ophthalmoplegia), Leigh's Syndrome, MNGTE         (Myopathy and external ophthalmoplegia; Neuropathy;         Gastro-Intestinal; Encephalopathy), Kearns-Sayre Syndrome (KSS),         NARP, Hereditary Spastic Paraparesis, Mitochondrial myopathy,         and Friedreich Ataxia; or     -   (7) a demyelinating neurological disorder selected from the         group consisting of optic neuritis, acute inflammatory         demyelinating polyneuropathy (AIDP), chronic inflammatory         demyelinating polyneuropathy (CIDP), acute transverse myelitis,         progressive multifocal leucoencephalopathy (PML), acute         disseminated encephalomyelitis (ADEM) or other hereditary         disorders (e.g., leukodystrophies, Leber's optic atrophy, and         Charcot-Marie-Tooth disease).

In some embodiments, the disease or disorder where administering DMF is helpful is a neutrophil mediated disease or disorder (e.g., an allergic disease or disorder, an inflammatory disease or disorder, an autoimmune disease or disorder, or a tumor).

Non-limiting examples of autoimmune diseases or disorders include autoimmune Addison's disease, autoimmune hemolytic anemia, autoimmune hepatitis, autoimmune inner ear disease, autoimmune lymphoproliferative syndrome (ALPS), autoimmune thrombocytopenic purpura (ATP), or autoimmune skin blistering diseases (AIBD).

Non-limiting examples of autoimmune skin blistering diseases include epidermolysis bullosa acquistita (EBA), pemphigoid disease (e.g., bullous pemphigoid, mucous membrane pemphigoid, or pemphigoid gestationis), IgA-mediated bullous dermatoses (e.g., Dermatitis Herpetiformis or Linear IgA Bullous Dermatosis), and pemphigus disease (e.g., IgA Pemphigus).

Non-limiting neutrophil mediated diseases or disorders also include an inflammatory skin or subcutaneous disease selected from the group consisting of Pyoderma Gangrenosum, Erosive Pustular Dermatosis of the Scalp, Sweet's Syndrome, Bowel-associated Dermatosis-arthritis Syndrome, Pustular Psoriasis, Acute Generalized Exanthematous Pustulosis, Keratoderma Blenorrhagicum, Sneddon-Wilkinson Disease, Amicrobial Pustulosis of the Folds, Infantile Acropustulosis, Transient Neonatal Pustulosis, Neutrophilic Eccrine Hidradenitis, Rheumatoid Neutrophilic Dermatitis, Neutrophilic Urticaria, Still's Disease, Erythema Marginatum, Unclassified Periodic Fever Syndromes/Autoinflammatory Syndromes, Bullous Systemic Lupus Erythematosus, and Neutrophilic Dermatosis of the Dorsal Hands (Pustular Vasculitis);

Non-limiting neutrophil mediated diseases or disorders also include:

-   -   a) an allergic condition selected from the group consisting of         anaphylaxis, allergic rhinitis and allergic asthma;     -   b) neutrophil mediated respiratory disease selected from the         group consisting of lung cancer, severe asphyxic episodes of         asthma, acute lung injury, and Acute Respiratory Distress         Syndrome;     -   c) an acute tissue injury selected from the group consisting of         acute kidney injury, ischemia reperfusion injury, sepsis, and         septicemia with multiorgan failure;     -   d) an inflammatory bowel disease selected from the group         consisting of ulcerative colitis, Crohn's disease, and         indeterminate colitis; and     -   e) sickle cell crisis or acute chest syndrome.

In some embodiments, the disease or disorder where administering DMF is helpful is a disease or disorder that is associated with aberrant PI3K/AKT signaling, including cancer, chronic inflammation and allergy, neurodegenerative disease, cardiovascular disease and metabolic diseases. Non-limiting examples of disease or disorders that are associated with aberrant PI3K/AKT signaling include all forms of cancer, precancerous lesions, cardiovascular disease, rheumatologic disease, pulmonary disease, dermatologic disease, gynecological diseases, vascular disease, neurologic disease, and infectious disease including bacterial, viral, retroviral, and parasitic diseases. In some embodiments, the disease or disorder to be treated is cancer. Non-limiting examples of cancer include breast cancer, lung cancer, ovarian cancer, uterine cancer, brain cancer, sarcoma, melanoma, leukemia, lymphoma, colorectal cancer, prostate cancer, and liver cancer. In some embodiments, the disease or disorder to be treated is rheumatologic disease, e.g., rheumatoid arthritis or osteoarthritis. In some embodiments, the disease or disorder to be treated is pulmonary disease, e.g., allergic rhinitis, chronic obstructive pulmonary disease (COPD).

In some embodiments, the disease or disorder where administering DMF is helpful is a disease or disorder that is associated with aberrant p38 MAPK signaling. Non-limiting examples of such diseases include COPD (including chronic bronchitis and emphysema), asthma, pediatric asthma, cystic fibrosis, sarcoidosis, idiopathic pulmonary fibrosis, allergic rhinitis, rhinitis, sinusitis, allergic conjunctivitis, conjunctivitis, allergic dermatitis, contact dermatitis, psoriasis, ulcerative colitis, inflamed joints secondary to rheumatoid arthritis or osteoarthritis, rheumatoid arthritis, pancreatitis, cachexia, inhibition of the growth and metastasis of tumours including non-small cell lung carcinoma, breast carcinoma, gastric carcinoma, colorectal carcinomas and malignant melanoma.

In some embodiments, the disease or disorder is a neurological disease or disorder. In some embodiments, the neurological disease or disorder is an autoimmune disease. In some embodiments, the neurological disease or disorder is a demyelinating disease or disorder.

In some embodiments, the neurological disease or disorder is selected from the group consisting of multiple sclerosis (MS), Huntington's disease, Alzheimer's disease, Parkinson's disease, optic neuritis, Devic disease, transverse myelitis, acute disseminated encephalomyelitis, adrenoleukodystrophy and adrenomyeloneuropathy, acute inflammatory demyelinating polyneuropathy (AIDP), chronic inflammatory demyelinating polyneuropathy (CIDP), acute transverse myelitis, progressive multifocal leucoencephalopathy (PML), acute disseminated encephalomyelitis (ADEM) and other hereditary disorders, such as leukodystrophies, Leber's optic atrophy, and Charcot-Marie-Tooth disease.

In some embodiments, the neurological disease or disorder is multiple sclerosis. In some embodiments, the MS is relapsing remitting MS, secondary progressive MS, primary progressive MS, progressive relapsing MS, or clinically isolated syndrome (CIS). In some embodiments, the neurological disease or disorder is a relapsing form of MS.

4.3.7 Vaccination Schedule

Various vaccination schedules are suitable for the methods described herein. In some embodiments, the subject receives the vaccine during the first dosing period. For example, the subject can receive the vaccine from one week to 24 weeks (e.g., 1 week, 2 weeks, 4 weeks, 8 weeks, 12 weeks, 16 weeks, 20 weeks, 24 weeks, or any ranges thereof) before the start of the first dosing period. In some embodiments, the subject receives the vaccine more than 24 weeks (e.g., more than 48 weeks, more than 96 weeks, or more than 5 years) before the start of the first dosing period. In some embodiments, the subject receives the vaccine during the first dosing period, for example, from 1 week to 48 weeks (e.g., 1 week, 2 weeks, 4 weeks, 8 weeks, 12 weeks, 16 weeks, 20 weeks, 24 weeks, 36 weeks, 48 weeks, or any ranges thereof) after the start of the first dosing period. In some embodiments, the subject receives the vaccine from 1 week to 48 weeks (e.g., 1 week, 2 weeks, 4 weeks, 8 weeks, 12 weeks, 16 weeks, 20 weeks, 24 weeks, 36 weeks, 48 weeks, or any ranges thereof) before the end of the first dosing period. In some embodiments, the subject receives at least one vaccine (e.g., 2 vaccines, 3 vaccines, 4 vaccines, or more than 4 vaccines) during the first dosing period. In some embodiments, each vaccine contains either a single antigen or multiple antigens.

In some embodiments, the first dosing period lasts from 1 month to 2 years (e.g., 1 month, 3 months, 6 months, 1 year, 2 year, or any ranges thereof). In some embodiments, the first dosing period is more than 2 years (e.g., more than 3 years, or more than 5 years). In some embodiments, the first dosing period lasts until the vaccine is administered to the subject.

In some embodiments, the second dosing period lasts from 1 week to 2 years (e.g., 1 week, 1 month, 3 months, 6 months, 1 year, 2 year, or any ranges thereof). In some embodiments, the second dosing period is more than 2 years (e.g., more than 3 years, more than 5 years, or for life). In some embodiments, the second dosing period lasts less than 1 week (e.g., 1, 2, 3, 4, 5, or 6 days). In some embodiments, the second dosing period is initiated within a week of (e.g., 1 day, 2 days, 3 days, 4 days, 5 days, 6 days, or 7 days after) the end of the first dosing period. In some embodiments, the second dosing period is initiated 1 week to 48 weeks (e.g., 1 week, 2 weeks, 4 weeks, 8 weeks, 12 weeks, 16 weeks, 20 weeks, 24 weeks, 36 weeks, 48 weeks, or any ranges thereof) after the end of the first dosing period. In some embodiments, the second dosing period is initiated on the same day on which the first dosing period ends. In other embodiments, the second dosing period is initiated on the same day as the subject receives a vaccine.

4.3.8 First and Second Doses

Various amounts of the fumarate agent can be used for the first and second doses in the methods described herein. In some embodiments, the first or second dose of the pharmaceutical composition contains a therapeutically effective amount of the fumarate agent. In some embodiments, the fumarate agent comprises MMF, DMF, or a combination thereof. In some embodiments, the fumarate agent comprises DMF. In some embodiments, the only active ingredient in the pharmaceutical composition is DMF. In a preferred embodiment, the pharmaceutical composition is Tecfidera® which is a controlled-release microtablet formulation containing 240 mg of DMF per capsule and the first or second dose of the pharmaceutical composition is effected by administering a Tecfidera® capsule to the subject twice daily or three times daily. In one embodiment, the first or second dose of the pharmaceutical composition is effected by administering a Tecfidera® capsule to the subject twice daily for a total daily dose of 480 mg.

In some embodiments, the second dose is no greater than the first dose. In some embodiments, the second dose is the same as the first dose. In some embodiments, the second dose is about 5% to about 95% (e.g., about 10%, about 20%, about 30%, about 40%, about 50%, about 60%, about 70%, about 80%, about 90%, or any ranges thereof) of the first dose. For example, the first dose can be a daily amount of about 480 mg of DMF, e.g., effected by a BID dosing, and the second dose can be 50% of the first dose, which is a daily amount of about 240 mg of DMF, which can also be effected by a BID dosing. In some embodiments, the second dose is less than 50% of the first dose. In some embodiments, the second dose is a daily amount of about 0 to about 480 mg fumarate agent. In some embodiments, the second dose is a daily amount of about 120 mg, about 240 mg, about 360 mg, or about 480 mg fumarate agent administered to the subject in 1, 2, or 3 (e.g., equal) doses. In some embodiments, the second dose is 0 mg fumarate agent.

In some embodiments, the subject is administered the same amount of fumarate agent as in the first dosing period after the second dosing period.

In some embodiments, the methods described herein further comprises administering a titration dose of the pharmaceutical composition prior to the first and/or second dosing periods. In some embodiments, the titration dose is administered to the subject for at least 7 days prior to beginning the first or second dosing period. In some embodiments, the fumarate agent is DMF and the titration dose is a daily dose of about 240 mg DMF administered BID for 7 consecutive days. In some embodiments, the fumarate agent is DMF and the titration dose is a daily dose of 360 mg DMF administered three times a day for 7 consecutive days.

The pharmaceutical composition can be in different forms. Non-limiting examples include pills, tablets, microtablets, pellets, powders, granules, micropellets, capsules (e.g., containing microtablets), liquid formulations for oral administration, and the form of dietary supplements. Methods for preparing pharmaceutical compositions in these forms are known in the art. Suitable pharmaceutically acceptable excipients for preparing the pharmaceutical compositions are also known in the art, for example, binders, fillers, disintegrants, glidants, lubricants, diluents, plasticizers, etc. as described in Remington's Pharmaceutical Science, 18^(th) Edition, 1990, Mack Publishing Company, Easton, Pa. (“Remington's”).

In some embodiments, the pharmaceutical composition is in the form of a capsule (such as a soft or hard gelatine capsule) containing DMF in the form of microtablets or micropellets (e.g., enteric-coated microtablets or micropellets). Suitable microtablets or micropellets are, without limitation, those having a mean diameter of 5,000 microns or less (e.g., 4,000 microns or less, 3,000 microns or less, 2,000 microns or less, 1,000 microns or less, or 500 microns or less) exclusive of any optional coating applied to the microtablets or micropellets. In some embodiments, the pharmaceutical composition is in the form of a capsule containing a pharmaceutical preparation consisting essentially of 60-240 mg (e.g., 120 mg, or 240 mg) of DMF in the form of enteric-coated microtablets. In some embodiments, the mean diameter of such microtablets is 1,000-5,000 microns, e.g., 1,000-3,000 microns or 2,000 microns. Methods for preparing microtablets or micropellets (e.g., enteric-coated microtablets or micropellets) comprising DMF are known in the art, for example, as described in U.S. Pat. No. 6,509,376 and incorporated by reference in its entirety herein.

The pharmaceutical composition suitable for the methods described herein include without limitation those formulated as an enterically coated immediate release dosage form, or a controlled release dosage form (e.g., a delayed release dosage form, a sustained release dosage form, a pulsatile release dosage form). In some embodiments, the controlled release dosage form is a gastric retentive dosage form. In some embodiments, the pharmaceutical composition is formulated as an enterically coated immediate release dosage form. In some embodiments, the pharmaceutical composition is formulated as a delayed release dosage form. The fumarate agent (e.g., DMF, MMF, or a combination thereof) can be administered in the form of a sustained or controlled release pharmaceutical formulation. Such formulation can be prepared by various technologies by a skilled person in the art. For example, the formulation can contain the therapeutic compound, a rate-controlling polymer (i.e., a material controlling the rate at which the therapeutic compound is released from the dosage form) and optionally other excipients. Some examples of rate-controlling polymers are hydroxy alkyl cellulose, hydroxypropyl alkyl cellulose (e.g., hydroxypropyl methyl cellulose, hydroxypropyl ethyl cellulose, hydroxypropyl isopropyl cellulose, hydroxypropyl butyl cellulose and hydroxypropyl hexyl cellulose), poly(ethylene)oxide, alkyl cellulose (e.g., ethyl cellulose and methyl cellulose), carboxymethyl cellulose, hydrophilic cellulose derivatives, and polyethylene glycol, compositions, e.g., those described in WO 2006/037342, incorporated herein by reference.

The pharmaceutical composition can be administered with or without food. In some embodiments, the pharmaceutical composition comprising the fumarate agent (e.g., DMF) is administered at least one hour before or at least one hour after food is consumed by the subject. In some embodiments, the pharmaceutical composition comprising the fumarate agent (e.g., DMF) is administered with food, for example, to reduce flushing.

In some embodiments, the neurological disorder is multiple sclerosis, wherein the first or second dose of the fumarate agent (e.g., DMF) is an amount that is effective in treating or preventing of multiple sclerosis, for example, in a subject who receives a vaccine before or during the first dosing period. For example, for DMF or MMF, the first or second dose can be a therapeutically effective amount range from about 1 mg/kg to about 50 mg/kg (e.g., from about 2.5 mg/kg to about 20 mg/kg or from about 2.5 mg/kg to about 15 mg/kg). Effective doses will vary, as recognized by those skilled in the art, dependent on route of administration, excipient usage, and the possibility of co-usage with other therapeutic treatments including use of other therapeutic agents.

In some embodiments, the first or second dose of DMF or MMF can be a therapeutically effective dose. In some embodiments, the therapeutically effective dose is a daily dose of from about 20 mg to about 1 g, for example, from about 100 mg to about 800 mg (e.g., from about 120 mg to about 720 mg, from about 240 mg to about 720 mg; or from about 480 mg to about 720 mg; or about 720 mg). The therapeutically effective dose of DMF or MMF can also be, for example, a daily dose of about 60 mg, about 80 mg, about 100 mg, about 120 mg, about 160 mg, about 200 mg, about 240 mg, about 320 mg, about 360 mg, about 400 mg, about 480 mg, about 600 mg, about 720 mg, about 800 mg, about 900 mg, about 1000 mg of DMF or MMF, or any ranges thereof. The dosages can be administered one or more times per day. For example, a 720 mg daily dose can be administered all at once or in separate administrations of 2, 3, 4, 5 or 6 (e.g., equal) doses. A 480 mg daily dose can be administered all at once or in separate administrations of 2, 3, 4, 5 or 6 (e.g., equal) doses. In some embodiments, the therapeutically effective dose of DMF or MMF is about 480 mg per day, effected by two equal, separate administrations, i.e., 240 mg per administration, at about 6 to about 12 hours apart in a day. In some embodiments, the therapeutically effective dose of DMF or MMF is about 720 mg per day, effected by three equal, separate administrations, i.e., 240 mg per administration, at about 4 to about 8 hours apart in a day. In some embodiments, the therapeutically effective dose of DMF or MMF is 300 mg to 1000 mg per day. In some embodiments, the therapeutically effective dose of DMF or MMF is 300 mg to 1000 mg per day delivered once daily. In some embodiments, the therapeutically effective dose of DMF or MMF is about 720 mg per day delivered once daily. In some embodiments, the therapeutically effective dose of DMF or MMF is about 480 mg per day delivered once daily.

In some embodiments, the first or second dose is administered to the subject by orally administering a dosage form that provides a total amount of about 60 mg to about 1000 mg of DMF. The dosage form can, for example, contain a total amount of DMF effective for treatment or prophylaxis of multiple sclerosis. The effective amount can range, but is not limited to, a total amount of about 60 mg to about 800 mg DMF, about 60 mg to about 720 mg DMF, 60 mg to about 500 mg DMF, about 60 mg to about 480 mg DMF, about 60 mg to about 420 mg DMF, about 60 mg to about 360 mg DMF, about 60 mg to about 240 mg DMF, about 60 mg to about 220 mg DMF, about 60 mg to about 200 mg DMF, about 60 mg to about 180 mg DMF, about 60 mg to about 160 mg DMF, about 60 mg to about 140 mg DMF, about 60 mg to about 120 mg DMF, about 60 mg to about 100 mg DMF, about 60 mg to about 80 mg DMF, about 80 mg to about 480 mg DMF, about 100 mg to about 480 mg DMF, about 120 mg to about 480 mg DMF, about 140 mg to about 480 mg DMF, about 160 mg to about 480 mg DMF, about 180 mg to about 480 mg DMF, about 200 mg to about 480 mg DMF, about 220 mg to about 480 mg DMF, about 240 mg to about 480 mg DMF, about 300 mg to about 480 mg DMF, about 360 mg to about 480 mg DMF, about 400 mg to about 480 mg DMF, about 450 mg to about 500 mg DMF, about 480 mg to about 500 mg DMF, about 80 to about 400 mg DMF, about 100 to about 300 mg DMF, about 120 to about 180 mg DMF, or about 140 mg to about 160 mg DMF.

The dosage form can contain, but is not limited to, a total amount of DMF of about 60 mg DMF, about 80 mg DMF, about 100 mg DMF, about 120 mg DMF, about 140 mg DMF, about 160 mg DMF, about 180 mg DMF, about 200 mg DMF, about 220 mg DMF, about 240 mg DMF, about 260 mg DMF, about 280 mg DMF, about 300 mg DMF, about 320 mg DMF, about 340 mg DMF, about 360 mg DMF, about 380 mg DMF, about 400 mg DMF, about 420 mg DMF, about 450 mg DMF, about 480 mg DMF, or about 500 mg DMF. In some embodiments, DMF is the only active ingredient in the dosage form.

In some embodiments, the fumarate agent is a compound that can be metabolized into MMF in vivo. And the first or second dose of the fumarate agent includes any amount of the compound that is equivalent to the amount of DMF or MMF described herein based on fumaric acid content.

In a healthy volunteer study, administration of 325 mg non-enteric coated aspirin 30 minutes prior to DMF dosing is found to reduce the occurrence and severity of flushing in the participating subjects. Subjects receiving a vaccine who experience flushing may be administered (e.g., 30 min. prior to DMF dosing) about 325 mg of aspirin to reduce flushing. Some patients who experience flushing with gastrointestinal side effects may reduce the dose to 120 mg DMF BID temporarily. Within a month, the effective dose of 240 mg DMF BID should be resumed.

In one embodiment, the method described herein further comprises administering to the subject one or more non-steroidal anti-inflammatory drugs (e.g., aspirin) before (for example, 10 minutes to an hour, e.g., 30 minutes before) administering the first or second dose of the pharmaceutical composition comprising the fumarate agent. In one embodiment, the subject administered the pharmaceutical composition comprising the fumarate agent takes the one or more non-steroidal anti-inflammatory drugs (e.g., aspirin) to reduce flushing. In another embodiment, the one or more non-steroidal anti-inflammatory drugs is selected from a group consisting of aspirin, ibuprofen, naproxen, ketoprofen, celecoxib, and combinations thereof. The one or more non-steroidal anti-inflammatory drugs can be administered in an amount of about 50 mg to about 500 mg before taking the dosage form described above. In one embodiment, a patient takes 325 mg aspirin before taking the pharmaceutical composition comprising the fumarate agent.

4.3.9 Immune Responses to the Vaccine

In any of the embodiments described herein, the subject can receive any type of vaccine (e.g., live or inactive vaccines). In a specific embodiment, the vaccine is a subunit vaccine. In some embodiments, the vaccine induces a T cell-dependent immune response (e.g., a T cell-dependent anamnestic humoral response, or a T cell-dependent primary response). In some embodiments, the vaccine induces a T cell-dependent anamnestic humoral immune response. In other embodiments, the vaccine induces a T cell-dependent neoantigen immune response.

In some embodiments, the vaccine induces an immune response against a virus, which can be, but is not limited to, adenovirus, arbovirus, coxsackievirus, cytomegalovirus, dengue virus, echinovirus, Ebola virus, echovirus, enterovirus, hepatitis type A, hepatitis type B, hepatitis type C, herpes simplex virus type I (HSV-I), herpes simplex virus type II (HSV-II), human immunodeficiency virus type I (HIV-I), human immunodeficiency virus type II (HIV-II), hantavirus, influenza, measles virus, mumps virus, papillomavirus, papovavirus, polio virus, respiratory syncytial virus, rhinovirus, rinderpest, rotavirus, rubella virus, SARS coronavirus or varicella. In some embodiments, the vaccine induces an immune response against a bacterium of a genus, which can be, but is not limited to, Chlamydia, Clostridium, Corynebacterium, Legionella, Mycobacterium, Mycoplasma, Neisseria, Rickettsia, or Streptococcus. In a specific embodiment, the bacterium is Clostridium tetani, Corynebacterium diphtheria, Neisseria meningitides, or Streptococcus pneumoniae. In some embodiments, the vaccine induces an immune response against a protozoan of a genus, which can be, but is not limited to, Kokzidioa, Leishmania, or Trypanosoma.

In some embodiments, the vaccine induces a T cell-independent immune response (e.g., a Type 1 or Type 2 T cell-independent immune response). In some embodiments, the subject receives one vaccine that induces a T cell-dependent immune response and another vaccine that induces a T cell-independent immune response. In some embodiments, the subject receives a vaccines that has been approved by the U.S. Food and Drug Administration (FDA) or other corresponding foreign regulatory authorities. Non-limiting examples of FDA approved vaccines for use include those listed under the tradenames of Biothrax, BCG Vaccine, TICE BCG, Tripedia, Infanrix, DAPTACEL, Pediarix, KINRIX, Pentacel, PedvaxHlB, ActHIB, Hiberix, Comvax, Havrix, VAQTA, Twinrix, Recombivax HB, Engerix-B, Gardasil, Cervarix, Afluria, FluLaval, FluMist, Fluarix, Fluvirin, Agriflu, Fluzone, Fluzone High-Dose and Fluzone Intradermal, Flucelvax, Flublok, FluMist Quadrivalent, Fluarix Quadrivalent, Fluzone Quadrivalent, FluLaval, Quadrivalent, Ixiaro, JE-Vax, M-M-Vax, M-M-R II, ProQuad, MENVEO, MenHibrix, Menactra, Menomune-A/C/Y/W-135, Pneumovax 23, Prevnar, Prevnar 13, Poliovax, IPOL, Imovax, RabAvert, ROTARIX, RotaTeq, ACAM2000, DECAVAC, TENIVAC, Adacel, Boostrix, Vivotif, TYPHIM Vi, Varivax, YF-Vax, and Zostavax. In some embodiments, the vaccine is a tetanus diphtheria toxoids vaccine (e.g., TENIVAC). In some embodiments, the vaccine is a KLH vaccine. In some embodiments, the vaccine is PNEUMOVAX 23. In some embodiments, the vaccine is meningococcal polysaccharide diphtheria conjugate vaccine, quadrivalent (i.e., MCV4; e.g., MENVEO, which is Meningococcal [Groups A, C, Y and W-135] Oligosaccharide Diphtheria CRM₁₉₇ Conjugate Vaccine). In some embodiments, the vaccine is selected from the group consisting of tetanus diphtheria toxoids vaccine, keyhole limpet hemocyanin vaccine, pneumovax-23 vaccine, and any combinations thereof. In some embodiments, the vaccine is selected from the group consisting of tetanus diphtheria toxoids vaccine, pneumovax-23 vaccine, and meningococcal polysaccharide diphtheria conjugate vaccine (quadrivalent). In some embodiments, the subject receives more than one vaccine during the first dosing period. In one embodiment, the patient receives more than one vaccine on the same day. Suitable doses, routes of administration, and immunization schedules for the vaccine can be any of those according to a FDA approved label for the vaccine.

Immune responses of a subject to a vaccine can be measured by any method known to those skilled in the art. In some embodiments, the step of determining the immune response comprises obtaining serum antibody (e.g., IgG or IgM) levels in the subject induced by the vaccine post-immunization (e.g., 4 weeks after immunization), obtaining the serum antibody (e.g., IgG or IgM) levels in the subject pre-immunization, and comparing the serum antibody levels in the subject pre- and post-immunization. Methods for measuring serum antibody levels are known in the art. In some embodiments, the serum antibody level in the subject increases less than 4-fold (e.g., less than 3-fold or less than 2-fold) from pre-immunization to 4 weeks after immunization. In some embodiments, the serum antibody level in the subject increases at least 2-fold (e.g., at least 4-fold or at least 10-fold) from pre-immunization to 4 weeks after immunization. In some embodiments, the serum antibody is IgG against tetanus diphtheria toxoids, keyhole limpet hemocyanin, or pneumovax-23, and the serum IgG level in the subject increases less than 4-fold (e.g., less than 3-fold or less than 2-fold) from pre-vaccination to 4 weeks after vaccination. In some embodiments, the serum IgG level in the subject increases at least 2-fold (e.g., at least 4-fold or at least 10-fold) from pre-immunization to 4 weeks after immunization.

In some embodiments, the immune response of the subject to the vaccine is characterized in that the serum antibody level in the subject increases at least 2-fold (e.g., at least 4-fold or at least 10-fold) from pre-immunization to 4 weeks after immunization, and the second dose is the same as the first dose. In some embodiments, the serum antibody is IgG against tetanus diphtheria toxoids, keyhole limpet hemocyanin, or pneumovax-23.

In some embodiments, the first dose is a daily dose of about 480 mg or about 720 mg of DMF divided into 1, 2, or 3 (e.g., equal) doses. In some embodiments, the second dose is a daily dose of about 120 mg, about 240 mg, or about 360 mg divided into 1, 2, or 3 (e.g., equal) doses. In some embodiments, the second dose is 0 mg fumarate agent. In some embodiments, the subject is administered the same amount of fumarate agent as in the first dosing period after the second dosing period.

4.4 Method 2. Screening for Lower Risk Dose

In some embodiments, the invention also provides a method of treating or preventing a disease or disorder (e.g., as described herein) in a subject who receives a vaccine, comprising screening a plurality of doses of a pharmaceutical composition comprising a fumarate agent selected from the group consisting of monomethyl fumarate, a compound that metabolizes into monomethyl fumarate in vivo, a deuterated analog thereof, a pharmaceutically acceptable salt thereof, and a combination thereof, by

-   -   (1) identifying a first group of subjects and at least a second         group of subjects, wherein both the first and second groups of         subjects receive a vaccine, wherein the first group of subjects         is treated with a first dose of the pharmaceutical composition,         and the second group of subjects is treated with a second dose         of the pharmaceutical composition; and     -   (2) determining a lower risk dose. In some embodiments, the         method further comprises administering the lower risk dose of         the pharmaceutical composition to the subject.

Methods for determining a lower risk dose of the pharmaceutical composition are known. In some embodiments, the lower risk dose is determined by comparing immune responses to the vaccine between the first and second groups of subjects, and the group of subjects treated with the lower risk dose have higher proportion of subjects with at least 2-fold increase in serum antibody levels induced by the vaccine from pre-vaccination to 4 weeks after vaccination. In some embodiments, the group of subjects treated with the lower risk dose have higher proportion of subjects having serum antibody levels induced by the vaccine not less than average serum antibody level observed in subjects administered with the vaccine but no fumarate agent at 4 weeks after vaccination.

Methods for determining a lower risk dose can also include comparing adverse effects observed between the first and second groups of subjects. In some embodiments, the group of subjects treated with the lower risk dose have a lower rate of a particular adverse effect (e.g., decreased incidence of headache, flushing, gastrointestinal event, or infection).

In some embodiments, the invention provides a method of treating or preventing multiple sclerosis in a subject in need thereof, comprising

-   -   (a) determining a subject's baseline lymphocyte count prior to         treatment;     -   (b) administering to the subject a first dose of a         pharmaceutical composition for a first dosing period, wherein         the pharmaceutical composition comprises a fumarate agent         selected from the group consisting of monomethyl fumarate, a         compound that metabolizes into monomethyl fumarate in vivo, a         deuterated analog thereof, a pharmaceutically acceptable salt         thereof, and a combination thereof,     -   (c) determining a subject's total lymphocyte count after the         first dosing period; and     -   (d) if the lymphocyte count after the first dosing period is 90%         of the baseline lymphocyte count or lower, do not administer         tetanus diphtheria toxoids vaccine, keyhole limpet hemocyanin         vaccine, pneumovax-23 vaccine, or any combinations thereof.

In some embodiments, the lymphocyte count after the first dosing period is about 10% to about 90% of the baseline lymphocyte count. In some embodiments, the lymphocyte count is about 10% to about 80% of the baseline lymphocyte count. In some embodiments, the lymphocyte count is about 10% to about 70% of the baseline. In some embodiments, the lymphocyte count is about 10% to about 50% of the baseline. In some embodiments, the lymphocyte count after the first dosing period is about 20% to about 90% of the baseline lymphocyte count. In some embodiments, the lymphocyte count is about 20% to about 80% of the baseline lymphocyte count. In some embodiments, the lymphocyte count is about 20% to about 70% of the baseline lymphocyte count. In some embodiments, the lymphocyte count is about 20% to about 60% of the baseline lymphocyte count. In some embodiments, the lymphocyte count is about 20% to about 50% of the baseline lymphocyte count. In some embodiments, the lymphocyte count is about 30% to about 90% of the baseline lymphocyte count. In some embodiments, the lymphocyte count is about 30% to about 80% of the baseline lymphocyte count. In some embodiments, the lymphocyte count is about 30% to about 70% of the baseline lymphocyte count. In some embodiments, the lymphocyte count is about 30% to about 60% of the baseline lymphocyte count. In some embodiments, the lymphocyte count is about 40% to about 90% of the baseline lymphocyte count. In some embodiments, the lymphocyte count is about 40% to about 80% of the baseline lymphocyte count. In some embodiments, the lymphocyte count is about 40% to about 70% of the baseline lymphocyte count. In some embodiments, the lymphocyte count is about 40% to about 70% of the baseline lymphocyte count. In some embodiments, the lymphocyte count is about 40% to about 60% of the baseline lymphocyte count. In some embodiments, the lymphocyte count is about 40% to about 50% of the baseline lymphocyte count. In some embodiments, the lymphocyte count after the first dosing period is about 10%, about 15%, about 20%, about 25%, about 30%, about 35%, about 40%, about 50%, about 55%, about 60%, about 65%, about 70%, about 75%, about 80%, about 85%, or about 90% of the baseline lymphocyte count.

Suitable fumarate agents, first and second doses of the pharmaceutical composition, vaccines, methods for determining immune responses to the vaccines, and diseases or disorders can be those described herein for Method 1.

The following examples are illustrative and do not limit the scope of the claimed embodiments.

5. EXAMPLES 5.1 Example 1: A Randomized, Open-Label Study to Assess the Effects of BG00012 on the Immune Response to Vaccination and on Lymphocyte Subsets in Subjects with Relapsing Forms of Multiple Sclerosis 5.1.1 Introduction

The primary objective of the study is to evaluate the effects of DMF administered over approximately 6 months on immune responses to vaccination with tetanus diphtheria toxoids vaccine (Td) [T cell-dependent anamnestic humoral response] and keyhole limpet hemocyanin (KLH) [T cell-dependent neoantigen response] in subjects with relapsing forms of MS.

Secondary objectives of this study in this study population are as follows: (1) to evaluate the effects of DMF administered over approximately 6 months on the immune response to vaccination with pneumovax-23 (PPSV23) [a mostly T cell-independent humoral response]; (2) to evaluate the pharmacodynamic effects of DMF on lymphocyte subtypes over 1 year of treatment; (3) to evaluate the pharmacodynamic effect of DMF on immunoglobulin levels over time; and (4) to evaluate the safety and tolerability of DMF.

5.1.2 DMF and Vaccines for the Study

DMF is a drug product formulated as enteric-coated microtablets in gelatin capsules (blue and white) for oral administration. Each capsule contains 120 mg DMF. Excipients for the manufacturing of the enteric-coated microtablets include microcrystalline cellulose, croscarmellose sodium, talc, colloidal anhydrous silica (colloidal silicon dioxide), magnesium stearate, triethyl citrate, methacrylic acid-methyl methacrylate copolymer, methacrylic acid-ethyl acrylate copolymer, simethicone, sodium lauryl sulfate, and polysorbate 80. Excipients for the manufacturing of the capsule shell include gelatin, titanium dioxide, and indigotin.

Tetanus diphtheria toxoids vaccine (Td [Tenivac®]; Sanofi Pasteur, Swiftwater, Pa.) is indicated for active immunization for the prevention of tetanus and diphtheria. It is used in this study to assess the integrity of a T cell-dependent anamnestic humoral response, as tetanus toxoid is an immunogen commonly administered to the general population.

Keyhole limpet hemocyanin (KLH) is used to test the integrity of a T cell-dependent primary response, as it is a novel immunogen for most individuals. KLH is administered as Immucothel® (Biosyn Arzneimittel AG, Fellbach, Germany), a hemocyanin product derived from KLH, which is obtained from the sea snail giant keyhole limpet. Immunoethel is approved for treatment of bladder cancer in several countries and is considered an investigational agent in the US, where it is used in clinical studies to produce an immune response.

Pneumovax® 23 (PPSV23; Merck & Co., Inc., Rahway, N.J., USA) is a 23-valent carbohydrate antigen vaccine approved for the prophylaxis of community-acquired pneumonia. Pneumococcal polysaccharide antigens are able to activate B cells without T cell help, and thus are considered type 2 T cell independent antigens. However, they are also able to induce an adaptive humoral immune response, due to a secondary signal of B cell activation provided by other immune cells and with some T cell involvement. PPSV23 is therefore be used in this study to assess a mostly T cell-independent humoral response.

5.1.3 Dosage Selection

The DMF dosage selected for this study (120 mg twice daily [BID] for the first week, 240 mg BID thereafter) is the approved DMF dosing regimen in patients with relapsing forms of MS in the United States (US).

Td (0.5 mL) and PPSV23 (0.5 mL) doses selected for this study are the current approved doses for these vaccines. KLH (1 mg) is the subcutaneous (SC) injection dose based on Immunoethel Investigator's Brochure.

Subjects with relapsing forms of MS between the ages of 18 and 55 years, with a known history of tetanus immunization.

5.1.4 Inclusion/Exclusion Criteria

Exemplary eligibility criteria at randomization include: (1) Male and female subjects of childbearing potential will practice effective contraception during the study and be willing and able to continue contraception for 30 days after their last dose of study treatment; (2) Aged 18 to 55 years old, inclusive, at the time of informed consent; (3) a confirmed diagnosis of a relapsing form of MS; and (4) a known history of tetanus immunization.

Exemplary exclusion criteria at randomization include: (1) Tetanus vaccination given less than 2 years or more than 15 years prior to Screening, or an anti-tetanus IgG titer at Screening that is greater than one-half the upper limit of detection for the assay; (2) Pneumococcal vaccination within the 5 years prior to Screening; (3) Previous exposure to KLH or vaccines containing KLH components (e.g., cancer vaccines); (4) Known hypersensitivity to KLH, PPSV23, or tetanus/diphtheria toxoids or any other administered vaccinations or their components (e.g., thimerosal); (5) Known allergy to shellfish; (6) History of, or positive test result at Screening for hepatitis C virus (HCV) antibody or hepatitis B virus (defined as positive for hepatitis B surface antigen [HBsAg] or hepatitis B core antibody [HBcAb]); (7) History of human immunodeficiency virus (HIV); (8) History of drug or alcohol abuse (as defined by the Investigator) within 2 years prior to Screening; (9) Current smoking or smoking within 6 months prior to Screening; (10) Any clinically significant (in the judgment of the Investigator) infectious illness (e.g., cellulitis, abscess, pneumonia, septicemia) within 30 days prior to Screening; (11) Any active bacterial or viral infection (as assessed by the Investigator) at randomization; (12) History of clinically significant (in the judgment of the Investigator) cardiovascular, dermatologic, endocrinologic, gastrointestinal, hematologic, hepatic, immunologic, metabolic, neurologic (other than MS), psychiatric, pulmonary, renal, urologic, and/or other major disease that would preclude participation in a clinical trial; (13) History of malignancy (subjects with basal cell carcinoma that has been completely excised prior to study entry remain eligible); (14) History of severe allergic or anaphylactic reactions or known drug hypersensitivity; (15) Any of the following abnormal blood tests at Screening that are confirmed on repeat testing 2 weeks later: (a) alanine transaminase/serum glutamate-pyruvate transaminase (ALT/SGPT), or aspartate transaminase/scrum glutamic-oxaloacetic transaminase (AST/SGOT), or gamma-glutamyl-transferase (GGT) ≥2 times the upper limit of normal (ULN); (b) leukocytes <3500/mm³; and (c) eosinophils >0.7×10³/μL or >0.7 GI/L; (16) Any of the following abnormal urine tests at Screening confirmed by a second urinalysis 2 weeks later: (a) proteinuria (1+ or greater); (b) hematuria, without known etiology; (c) glycosuria, without known etiology; (17) Any previous treatment with Fumaderm® or DMF (FAG-201); (18) Any type of live vaccine within 4 weeks prior to randomization, including but not limited to measles/mumps/rubella vaccine, varicella zoster virus vaccine, oral polio vaccine, and nasal influenza vaccine; (19) Prior treatment with any of the following: cladribine, mitoxantrone, fingolimod, alemtuzumab, total lymphoid irradiation, T-cell or T-cell receptor vaccination, any therapeutic monoclonal antibody, with the exception of Tysabri® (natalizumab) (see exclusion #20); (20) Treatment with Tysabri (natalizumab) within 1 year prior to randomization; (21) Treatment with any of the following medications or procedures within the 6 months prior to randomization: cyclosporine, azathioprine, teriflunomide, methotrexate, mycophenolate mofetil, intravenous immunoglobulin, plasmapheresis or cytapheresis; (22) Treatment with any of the following within 2 weeks prior to randomization: subcutaneous or oral glatiramer acetate, interferon-α, interferon-β; (23) Treatment with any of the following within 4 weeks prior to randomization: Steroids (intravenous [IV] or oral corticosteroid treatment, including agents that may act through the corticosteroid pathway [e.g., low dose naltrexone]), 4-aminopyridine or related products; and (24) Treatment with another investigational drug or approved therapy for investigational use within the 6 months prior to randomization.

5.1.5 Endpoints

The primary end points of this study are (1) the proportion of subjects with a ≥2-fold rise in anti-tetanus serum immunoglobulin G (IgG) levels from pre-vaccination to 4 weeks after Td vaccination; and (2) The proportion of subjects with a ≥2-fold rise in anti-KLH serum IgG levels from pre-vaccination to 4 weeks after the final KLH vaccination.

Secondary end points for this study are (1) the proportion of subjects with a ≥4-fold rise in anti-tetanus serum IgG levels from pre-vaccination to 4 weeks after Td vaccination; (2) the proportion of subjects with a ≥4-fold rise in anti-KLH serum IgG levels from pre-vaccination to 4 weeks after the final KLH vaccination; (3) the proportion of subjects with a ≥2- and a ≥4-fold rise in anti-pneumococcal IgG levels from pre-vaccination baseline to 4 weeks after PPSV23 vaccination; (4) Anti-tetanus, anti-KLH, and anti-pneumococcal immunoglobulin levels over time; (5) Change over time in lymphocyte subsets, including: T cells, B cells, NK cells (e.g., Total T cells: CD4+/CD8+; Total B cells; Total NK); (6) Additional analysis of lymphocyte subsets which can include: Treg Panel (total Treg, Resting/naïve Treg; and/or active Treg); T-cell panel (Naïve; Effector; Central/Effector Memory; and/or Activated (expressing HLA-DR/CD38)); (7) Myeloid NK panel (Monocytes: CD16+ (non-classical)/CD16− (classical); Dendritic cells: myeloid/plasmacytoid; and/or NKs: CD56^(dim)/CD56^(bright)); B cell panel (Translational; Naïve; Memory: IgD+/IgD−; and/or Plasmablast); and (8) Safety parameters, including incidence of all AEs, including those leading to treatment discontinuation and study withdrawal, and all serious adverse events (SAEs); clinical laboratory shifts in reported values; and clinically significant changes in vital sign measurements.

In addition, Ribonucleic acid (RNA) and peripheral blood mononuclear cells (PBMCs) are collected in certain subjects evaluate lymphocyte subsets. PBMCs are separated and frozen for testing at a later time at the Sponsor's discretion.

5.1.6 Treatment Schedule

Approximately 68 subjects are enrolled in the study. Subjects are randomized in a 1:1 ratio to Group 1 (DMF treatment plus immunizations) or Group 2 (immunizations alone).

Group 1 subjects are treated with DMF 120 mg BID for first 7 days and 240 mg BID thereafter up to 48 weeks. Table 1 shows a detailed schedule of events for Group 1 subjects.

At Week 24, subjects in Group 1 receive Td, PPSV23, and KLH vaccinations. At 2 and 4 weeks after the Week 24 vaccination, subjects receive an additional KLH vaccination (Weeks 26 and 28). Anti-tetanus and anti-pneumococcal IgG titers are measured just prior to and at 4 and 8 weeks after the Week 24 vaccinations (i.e., Weeks 24, 28, and 32). Anti-KLH IgG titers are measured just prior to and at 4, 8, and 12 weeks after the Week 24 vaccination (i.e., Weeks 24, 28, 32, and 36). (Anti-tetanus titers are also measured at Screening, as part of the eligibility criteria). Blood samples for lymphocyte subset analysis, as well as blood samples for determination of each subject's complete blood count (CBC) with differential, are collected at Screening, Baseline (Day 1), and Weeks 12, 24, 36, and 48. Clinical samples for analysis of blood chemistries and urinalysis are collected at Screening and at Weeks 24 and 48. A serum pregnancy test is performed at Screening, as part of the eligibility criteria. Urine pregnancy tests are performed at Baseline (Day 1), and Weeks 12, 24, 26, 28, 32, 36, and 48. Vital signs, AEs, and concomitant therapies are assessed at every clinic visit. A final follow-up clinic visit at which safety assessments are performed occurs 4 weeks after the final dose of DMF in subjects who do not continue treatment with commercial DMF. Subjects who plan to continue treatment with commercial DMF after Week 48 are contacted by telephone 2-4 weeks after their last study dose to ensure transition has taken place. If for any reason they have not started commercial DMF, they are required to have a final follow-up clinic visit 4 weeks after their last study dose.

Group 2 subjects receive the same vaccinations and assessments over a 12-week period according to the schedule in Group 1, but with vaccinations starting on Day 1. That is, subjects receive Td, PPSV23, and KLH vaccinations at Baseline (Day 1) and an additional KLH vaccination at Weeks 2 and 4. Anti-tetanus and anti-pneumococcal IgG titers are measured just prior to and at 4 and 8 weeks after Baseline (Day 1). Anti-KLH IgG titers are measured just prior to and at 4, 8, and 12 weeks after the Day 1 vaccination. (Anti-tetanus titers are also measured at Screening, as part of the eligibility criteria). Blood samples for lymphocyte subset analysis (as well as CBC with differential for laboratory safety analysis) are collected at Screening, Baseline (Day 1), and Week 12. Clinical samples for analysis of blood chemistries and urinalysis are collected at Screening and Week 12 and at Screening, Baseline (Day 1), and Week 12, respectively. A serum pregnancy test is performed at Screening, as part of the eligibility criteria. Urine pregnancy tests are performed at Baseline (Day 1), and Weeks 2, 4, and 12. Vital sign measurements, AEs, and concomitant therapies are performed at every clinic visit. After completing the study, Group 2 subjects may be eligible to begin treatment with commercial DMF if deemed appropriate. Table 2 shows a detailed schedule of events for Group 2 subjects.

Subjects randomized to Group 1 (DMF treatment plus immunizations) have 9 clinic visits: Screening, Baseline (Day 1), and Weeks 12, 24, 26, 28, 32, 36, and 48. Subjects who do not continue treatment with commercial DMF after Week 48 have a final follow-up clinic visit 4 weeks after the final dose. Subjects who plan to continue treatment with commercial DMF after Week 48 are contacted by telephone 2-4 weeks after their last study dose to ensure transition has taken place. If for any reason they have not started commercial DMF they are required to have a final follow-up clinic visit 4 weeks after their last study dose.

Subjects randomized to Group 2 (immunizations alone) have 6 clinic visits: Screening, baseline (Day 1), and Weeks 2, 4, 8, and 12.

5.1.7 Efficacy Analysis

Analysis of the primary endpoint for the Td and KLH vaccinations is based on evaluable subjects (i.e., subjects who are appropriately vaccinated per protocol; are ≥70% compliant with DMF [Group 1 only], and have non-missing IgG levels at pre-vaccination and 4 weeks after final vaccination).

TABLE 1 Group 1 Schedule of Events Screening (w/in 28 Week 12 Week 24 Week 26 Week 28 Week 32 Week 36 Week 48 Follow-Up days (Day (Day (Day (Day (Day (Day (Day (4 weeks ± 5 Tests and before Baseline 84 ± 3 168 ± 3 182 ± 3 196 ± 3 224 ± 3 252 ± 3 336 ± 3 days after Assessments¹ Baseline) (Day 1) days) days) days) days) days) days) days)/W/D² final dose)² Informed consent³ X Medical history X Physical X X examination Vital signs⁴ X X X X X X X X X X Hepatitis B and C X screen Hematology (CBC X X X  X⁵ X X X with differential) Blood chemistry X  X⁵ X X Urinalysis X  X⁵ X X Scrum pregnancy X test⁶ Urine pregnancy X X X X X X X X test⁶ Dispense DMF X X X X X X DMF DMF is to be taken as 120 mg BID for the first 7 days and thereafter as 240 mg BID. Subjects are administration to be instructed to take DMF orally, by swallowing the capsules whole without chewing, and with or without food. Tetanus toxoid X vaccine⁷ PPSV23 vaccine⁷ X Anti-tetanus and Anti-tetanus  X⁵  X⁵ X anti-pneumococcal only antibody assays KLH vaccine⁷ X X X KLH antibody  X⁵  X⁵ X X assay Lymphocyte X X X  X⁵ X X X subset analysis Concomitant X X X X X X X X X X therapy and procedures SAE recording X X X X X X X X X X AE recording X X X X X X X X X RNA collection⁸ X X  X⁵ X X X PBMC collection⁸ X  X⁵ X X ¹All tests and assessments will be performed before dispensing study treatment. ²Subjects who discontinue treatment prematurely are withdrawn from the study and have a Withdrawal visit within 4 weeks after taking their final study dose. Subjects who do not continue treatment with commercial DMF after Week 48/early withdrawal have a final follow-up clinic visit 4 weeks after their final study dose. Subjects who plan to continue treatment with commercial DMF after Week 48 are contacted by telephone 2-4 weeks after their last study dose to ensure transition has taken place. If for any reason they have not started commercial DMF they are required to have a final follow-up clinic visit 4 weeks after their last study dose. ³Written informed consent will be obtained prior to performing any study-related procedures, and may be obtained prior to Screening if a washout period is required for prior therapy. ⁴Vital signs include height (measured at Screening only), weight, diastolic and systolic blood pressure, heart rate, and temperature. Subjects will be seated for 5 minutes prior to having their pulse and blood pressure measured. ⁵Blood as well as urine samples will be collected prior to immunization. ⁶Females of childbearing potential only. Results will be known to be negative prior to dispensing DMF and immunization. ⁷Subjects are observed for any severe local or systemic reactions for 45 minutes following immunization. ⁸RNA and PBMC are collected in subjects who have signed a separate Future Scientific Research informed consent form.

TABLE 2 Group 2 Schedule of Events Week 2 Week 4 Week 8 Week 12 Screening (Day (Day (Day (Day Tests and (within 28 days Baseline 14 ± 3 28 ± 3 56 ± 3 84 ± 3 Assessments¹ before Baseline) (Day 1) days) days) days) days)/W/D² Informed X consent³ Medical history X Physical X examination Vital signs⁴ X X X X X X Hepatitis B and X C screen Hematology X  X⁵ X (CBC with differential) Blood chemistry X X Urinalysis X  X⁵ X Serum X pregnancy test⁶ Urine pregnancy X X X X test⁶ Tetanus toxoid X vaccine⁷ PPV23 vaccine⁷ X Anti-tetanus and Anti-tetanus only  X⁵  X⁵ X anti- pneumococcal antibody assays KLH vaccine X X X KLH antibody  X⁵  X⁵ X X assay Lymphocyte X  X⁵ X subset analysis Concomitant X X X X X X therapy and procedures SAE recording X X X X X X AE recording X X X X X RNA collection⁸  X⁵ PBMC  X⁵ X collection⁸ ¹All tests and assessments will be performed prior to immunization. ²In subjects who are withdrawn from the study, a Withdrawal Visit is performed within 4 weeks after their last immunization. ³Written informed consent will be obtained prior to performing any study-related procedures, and may be obtained prior to Screening if a washout period is required for prior therapy. ⁴Vital signs include height (measured at Screening only), weight, diastolic and systolic blood pressure, heart rate, and temperature. Subjects will be seated for 5 minutes prior to having their pulse and blood pressure measured. ⁵Blood as well as urine samples will be collected prior to immunization. ⁶Females of childbearing potential only. Results will be known to be negative prior to immunization. ⁷Subjects are observed for any severe local or systemic reactions for 45 minutes following immunization. ⁸RNA and PBMC are collected in subjects who have signed a separate Future Scientific Research informed consent form.

5.2 Example 2: An Open-Label Study to Assess the Immune Response to Vaccination in Tecfidera® (BG00012)-Treated Versus Interferon-Treated Subjects with Relapsing Forms of Multiple Sclerosis 5.2.1 LIST OF ABBREVIATIONS

The following abbreviations and definitions are used in this study protocol:

AE adverse event BID twice daily CI confidence interval CRF case report form EDC electronic data capture GCP Good Clinical Practice ICF informed consent form ICH International Conference on Harmonisation IFN interferon IgG immunoglobulin G MCV4 meningococcal polysaccharide diphtheria conjugate vaccine (quadrivalent) MS multiple sclerosis PHI protected health information PPSV23 23-valent pneumococcal polysaccharide vaccine RRMS relapsing-remitting multiple sclerosis SAE serious adverse event SUSAR suspected unexpected serious adverse reaction Td tetanus diphtheria toxoids vaccine US United States

5.2.2 Synopsis

This is a brief summary of the study protocol.

Existing Multiple Sclerosis Treatment (Not Supplied by the Sponsor) include Tecfidera® (dimethyl fumarate) and non-pegylated interferon (IFN; e.g., Avonex®, Betaseron®, Rebif®, Extavia®).

5.2.2.1. Study Objectives

Primary

The primary objective of the study is to evaluate the immune response to vaccination with Td in subjects with relapsing forms of MS who have been treated with Tecfidera versus those treated with non-pegylated IFN.

Secondary

The secondary objective of the study is to evaluate the immune response to vaccination with PPSV23 and MCV4.

5.2.2.2. Study Endpoints

Primary

The primary endpoint of the study is:

-   -   The proportion of subjects with a ≥2-fold rise in anti-tetanus         serum immunoglobulin G (IgG) levels from pre-vaccination to 4         weeks after Td vaccination.

Secondary

The secondary endpoints of the study are:

-   -   The proportion of subjects with a ≥4-fold rise in anti-tetanus         serum IgG levels from pre-vaccination to 4 weeks after Td         vaccination.     -   The proportion of subjects with a ≥2-fold and a ≥4-fold rise in         anti-pneumococcal serum IgG levels against serotypes 3 and 8         from pre-vaccination to 4 weeks after PPSV23 vaccination.     -   The proportion of subjects with a ≥2-fold and a ≥4-fold rise in         anti-meningococcal serum IgG levels against serotype C from         pre-vaccination to 4 weeks after MCV4 vaccination.     -   The geometric mean titer ratios from pre-vaccination to 4 weeks         after Td, PPSV23, and MCV4 vaccinations.     -   Incidence of adverse events (AEs) and serious adverse events         (SAEs).     -   Clinical laboratory shifts in reported values.     -   Clinically significant changes in vital sign measurements.

Exploratory

The exploratory endpoints of the study are:

-   -   The proportion of subjects with a ≥2-fold and a ≥4-fold rise in         anti-diphtheria toxoid serum IgG levels from pre-vaccination to         4 weeks after MCV4 vaccination.     -   The anti-diphtheria geometric mean titer ratio from         pre-vaccination to 4 weeks after MCV4 vaccination.     -   The proportion of subjects with anti-tetanus and         anti-meningococcal seroprotective levels at 4 weeks after Td and         MCV4 vaccinations.

5.2.2.3. Study Design

This is an open-label, multicenter study to evaluate the immune response to vaccination in subjects with relapsing forms of MS who have been treated for at least 6 months with the approved dose of Tecfidera (240 mg twice daily [BID]) or who have been treated for at least 3 months with the approved dose of a non pegylated IFN (e.g., Avonex, Betaseron, Rebif, Extavia).

After a 28-day Screening Period, eligible subjects will be enrolled and assigned as appropriate into either Group 1 (currently treated with Tecfidera) or Group 2 (currently treated with non-pegylated IFN). Throughout the study, subjects will remain on their existing, stable dosing regimen of Tecfidera or non pegylated IFN.

Subjects will come to the clinic on Day 1 and have blood samples drawn for pre vaccination anti-tetanus, anti pneumococcal, anti meningococcal, and anti-diphtheria IgG titers. All subjects will receive 3 vaccinations: Td, PPSV23, and MCV4. They will return to the clinic at Week 4 for their final study visit, at which time blood samples will be drawn for post-vaccination IgG titers.

Subjects who receive at least 1 dose of a vaccine should remain in the study and attend the Week 4 Visit. Subjects who receive at least 1 dose of a vaccine but would like to withdraw from the study prematurely will be asked to return to the clinic for an Early Withdrawal Visit, at which time blood samples will be drawn for IgG titers.

Safety evaluations in this study will include blood samples for complete blood count with differential and blood chemistry, urine pregnancy tests, and vital signs at Day 1 and Week 4, as well as ongoing collection of AEs, SAEs, and concomitant medications.

The subjects' neurologist or primary healthcare provider will manage their MS care before, during, and after study participation.

This study will be conducted at approximately 10 to 15 sites in the United States, and the number of planned subjects will be 70 (approximately 35 in each group)

5.2.2.4. Study Population

Subjects with relapsing forms of MS between the ages of 18 and 55 years, inclusive, with a known history of tetanus immunization and on a stable approved dose of either Tecfidera (240 mg BID) for ≥6 months or a non pegylated IFN for ≥3 months.

5.2.2.5. Treatment Groups

Subjects treated with Tecfidera will be assigned to Group 1. Subjects treated with non pegylated IFN will be assigned to Group 2.

All subjects will receive the same 3 vaccinations on Day 1 intramuscularly in the specified order:

-   -   1. Td 0.5 mL     -   2. PPSV23 0.5 mL     -   3. MCV4 0.5 mL

5.2.2.6. Study Duration

Subjects will have 3 clinic visits: Screening, Day 1, and Week 4. The duration of study participation will be approximately 8 weeks.

5.2.2.7. Criteria for Evaluation

Efficacy

Anti-tetanus, anti pneumococcal, anti meningococcal, and anti-diphtheria IgG levels at pre vaccination (Day 1) and at Week 4

Safety

The following safety assessments will be performed:

-   -   Vital sign measurements     -   Physical examination     -   Hematology and blood chemistry     -   Serum and urine pregnancy testing     -   Monitoring and recording of AEs     -   Monitoring and recording of concomitant therapy and procedures

5.2.2.8. Statistical Methods

No formal statistical testing is planned. The proportion of responders to each vaccine antigen will be estimated with 95% confidence intervals (CIs) using the exact method. Differences in the proportion of subjects with an antibody response between Group 1 and Group 2 will also be estimated with 95% CIs using the exact method. The IgG level to each antigen will also be summarized by geometric mean concentration for each group with 95% CI as well as the ratio between the 2 groups.

All safety data will be summarized using descriptive statistics. Incidence of AEs will be summarized using frequency distribution tables by group, overall, by severity, and by relationship to vaccines. Change from baseline in laboratory values and vital signs will also be descriptively summarized by group.

No interim analysis will be performed.

5.2.2.9. Sample Size Determination

The sample size for this study is not based on formal hypothesis testing, but on the precision of estimated response rates. The 95% CIs for the difference between Groups 1 and 2 in the proportion of vaccination responders will be provided to quantify the variability in the differences of response rates.

Assuming a response rate of 95% to Td in Group 2 (the reference group) and a range of hypothetical response rates in Group 1 (the test group), an evaluable size of 32 subjects per group would provide the following 95% CIs for the difference between groups (Group 1-Group 2) in the proportion of vaccination responders:

Group 1 Difference 95% CI for the Response Rate (Group 1 − Group 2) Difference 95% 0 [−13.8%, 13.8%]  75% −20% [−39.9%, 0.1%]  70% −25% [−45.7%, −4.3%] 65% −30% [−51.3%, −8.7%] 55% −40%  [−61.9%, −18.1%]

The analysis population for the primary endpoint of ≥2-fold rise in anti-tetanus serum IgG levels comprises subjects who are appropriately vaccinated per protocol, have not taken any concomitant medication that could impact immune responses, and who have nonmissing pre-vaccination and post vaccination IgG levels with a pre-vaccination level less than or equal to one half the upper limit of detection for the assay. It is anticipated that a total sample size of approximately 70 subjects (35 subjects per group) will need to be enrolled in order to obtain a total of 64 evaluable subjects (32 subjects per group). The sample size determination takes into account an approximate 10% loss of evaluable subjects.

5.2.3 Schedule of Events

TABLE 3 Schedule of Events Screening Week 4 (Day 28 ± (Within 28 days 3 days) or Early Tests and Assessments Before Day 1) Day 1 Withdrawal Informed Consent¹ X Inclusion/Exclusion Criteria X X Medical History X Vital Signs² X X X Physical Examination X Hematology (CBC With X  X³ X Differential) Blood Chemistry X  X³ X Pregnancy Tests⁴ Serum Urine Urine Blood Collection for Anti-Tetanus  X³ X Anti-Tetanus, Only Anti-Pneumococcal Anti-Meningococcal, and Anti-Diphtheria IgG Titers Vaccines Td⁵ X PPSV23⁵ X MCV4⁵ X SAE and Concomitant X ------------------------------------------------------------- X Therapy and Procedures Recording AEs Recording X ------------------------------ X AEs = adverse events; CBC = complete blood count; IgG = immunoglobulin G; MCV4 = meningococcal polysaccharide diphtheria conjugate vaccine (quadrivalent); PPSV23 = 23-valent pneumococcal polysaccharide vaccine; SAEs = serious adverse events; Td = tetanus diphtheria toxoids vaccine. ¹Written informed consent will be obtained prior to performing any study-related procedures. ²Vital signs will include height (measured at Screening only), weight, diastolic and systolic blood pressure, heart rate, and temperature. Subjects will be seated for 5 minutes prior to having their pulse and blood pressure measured. ³Blood samples will be collected prior to vaccine administration. ⁴Females of childbearing potential only. Results will be known to be negative prior to vaccine administration. ⁵Subjects will be observed in the clinic for at least 30 minutes following their final vaccine administration.

5.2.4 Study Objectives and Endpoints 5.2.4.1. Objectives

Primary Objective

The primary objective of the study is to evaluate the immune response to vaccination with Td in subjects with relapsing forms of MS who have been treated with Tecfidera versus those treated with non pegylated IFN.

Secondary Objective

The secondary objective of the study is to evaluate the immune response to vaccination with PPSV23 and MCV4.

5.2.4.2. Endpoints

Primary Endpoint

The proportion of subjects with a ≥2-fold rise in anti tetanus serum immunoglobulin G (IgG) levels from pre-vaccination to 4 weeks after Td vaccination.

Secondary Endpoints

-   -   The proportion of subjects with a ≥4 fold rise in anti tetanus         serum IgG levels from pre vaccination to 4 weeks after Td         vaccination.     -   The proportion of subjects with a ≥2-fold and a ≥4-fold rise in         anti pneumococcal serum IgG levels against serotypes 3 and 8         from pre vaccination to 4 weeks after PPSV23 vaccination.     -   The proportion of subjects with a ≥2-fold and a ≥4-fold rise in         anti meningococcal serum IgG levels against serotype C from         pre-vaccination to 4 weeks after MCV4 vaccination.     -   The geometric mean titer ratios from pre-vaccination to 4 weeks         after Td, PPSV23, and MCV4 vaccinations.     -   Incidence of adverse events (AEs) and serious adverse events         (SAEs).     -   Clinical laboratory shifts in reported values.     -   Clinically significant changes in vital sign measurements.

Exploratory Endpoints

-   -   The proportion of subjects with a ≥2-fold and a ≥4-fold rise in         anti-diphtheria toxoid serum IgG levels from pre-vaccination to         4 weeks after MCV4 vaccination.     -   The anti-diphtheria geometric mean titer ratio from         pre-vaccination to 4 weeks after MCV4 vaccination.     -   The proportion of subjects with anti-tetanus and         anti-meningococcal seroprotective levels at 4 weeks after Td and         MCV4 vaccinations.

5.2.5 Study Design 5.2.5.1. Study Overview

This is an open-label, multicenter study to evaluate the immune response to vaccination in subjects with relapsing forms of MS who have been treated for at least 6 months with the approved dose of Tecfidera (240 mg BID) or who have been treated for at least 3 months with an approved dose of a non pegylated IFN (e.g., Avonex, Betaseron, Rebif, Extavia). This study will be conducted at approximately 10 to 15 sites in the US.

After a 28-day Screening Period, approximately 70 eligible subjects will be enrolled and assigned as appropriate into either Group 1 (currently treated with Tecfidera) or Group 2 (currently treated with non-pegylated IFN), with approximately 35 subjects in each group.

Throughout the study, subjects will remain on their existing, stable dosing regimen of Tecfidera or non pegylated IFN.

Subjects will come to the clinic on Day 1 and have blood samples drawn for pre-vaccination anti-tetanus, anti pneumococcal, anti meningococcal, and anti diphtheria IgG titers. All subjects will receive 3 vaccinations: Td, PPSV23, and MCV4. They will return to the clinic at Week 4 for their final study visit, at which time blood samples will be drawn for post-vaccination IgG titers.

Subjects who receive at least 1 dose of a vaccine should remain in the study and attend the Week 4 Visit. Subjects who receive at least 1 dose of a vaccine but would like to withdraw from the study prematurely will be asked to return to the clinic for an Early Withdrawal Visit, at which time blood samples will be drawn for IgG titers.

Safety evaluations in this study will include blood samples for complete blood count with differential and blood chemistry, urine pregnancy tests, and vital signs at Day 1 and Week 4, as well as ongoing collection of AEs, SAEs, and concomitant medications as detailed in Table 3: Schedule of Events.

The subjects' neurologist or primary healthcare provider will manage their MS care before, during, and after study participation.

5.2.5.2. Overall Study Duration and Order of Study Procedures

In both groups, subjects will have 3 clinic visits: Screening, Day 1, and Week 4. The duration of study participation will be approximately 8 weeks. The following sections outline the timing and order of procedures conducted at each study visit. The procedures are listed in the order of preferred collection by the Sponsor to enhance data clarity. Altering the order is not considered a protocol deviation with the exception of the timing of blood collection in relation to vaccination (i.e., blood samples for pre-vaccination titers will be collected before vaccinations are given) and the order of vaccine administration.

5.2.5.3. Screening Visit

Subjects will be screened and meet eligibility criteria for the study within 28 days prior to study entry.

At the Screening Visit, informed consent will be given before any screening activities are conducted. Other procedures to be conducted during the Screening Visit, in preferred order, are listed below:

-   -   Concomitant therapy and procedure recording     -   Medical history     -   Vital signs     -   Physical examination     -   Review of inclusion/exclusion criteria (except laboratory         results)     -   Collection of blood samples for anti-tetanus IgG titer,         hematology, blood chemistry, and serum pregnancy test     -   AE assessment and reporting

5.2.5.4. Day 1 Visit

Subjects who pass screening will return to the clinic for the Day 1 Visit.

At the Day 1 Visit, the following procedures will be completed before study vaccines are administered and are listed in preferred order:

-   -   AE and SAE assessment and recording     -   Concomitant therapy and procedure recording     -   Review of inclusion/exclusion criteria     -   Urine pregnancy test (females only)—do not vaccinate subject         unless pregnancy has been excluded with a negative pregnancy         test     -   Vital signs     -   Collection of blood samples for anti-tetanus, anti-pneumococcal,         anti meningococcal, and anti-diphtheria IgG titers; hematology;         and blood chemistry

After completing these assessments, study vaccines will be administered in the following order:

-   -   1. Td     -   2. PPSV23     -   3. MCV4

Subjects will remain at the clinic for at least 30 minutes after their final vaccination for observation.

5.2.5.5. Week 4/Early Withdrawal Visit

Subjects in both groups will have a clinic visit 4 weeks after vaccination. Subjects who have received at least 1 vaccination but withdraw prematurely from the study will be asked to return to the clinic for an Early Withdrawal Visit.

Procedures to be conducted during the Week 4/Early Withdrawal Visit, in preferred order, are listed below:

-   -   AE and SAE assessment and recording     -   Concomitant therapy and procedure recording     -   Urine pregnancy test (females only)     -   Vital signs     -   Collection of blood samples for anti-tetanus, anti-pneumococcal,         anti meningococcal, and anti-diphtheria IgG titers; hematology;         and blood chemistry

5.2.5.6. End of Study

The end of study is last subject, last visit for final collection of data.

5.2.6 Selection of Subjects 5.2.6.1. Inclusion Criteria

Unless otherwise specified, to be eligible to participate in this study, candidates will meet the following eligibility criteria at Screening and on Day 1 or at the timepoint specified in the individual eligibility criterion:

-   -   1. Ability to understand the purpose and risks of the study and         provide signed and dated informed consent and authorization to         use protected health information (PHI) in accordance with         national and local subject privacy regulations.     -   2. Aged 18 to 55 years old, inclusive, at the time of informed         consent.     -   3. Women of childbearing potential will practice appropriate         contraception (per the local Tecfidera or non-pegylated IFN         prescribing information) as determined by the Investigator.     -   4. Will have a confirmed diagnosis of RRMS per the 2010 McDonald         criteria [Polman 2011].     -   5. Will have a known tetanus immunization history with most         recent tetanus vaccination given 2 to 15 years prior to         Screening and an anti-tetanus IgG titer at Screening that is         less than or equal to one-half the upper limit of detection for         the assay.     -   6. Will have been on a stable approved dose of Tecfidera (240 mg         BID) [Group 1] for ≥6 months or on a stable approved dose of a         non-pegylated IFN (e.g., Avonex, Betaseron, Rebif, Extavia)         [Group 2] for ≥3 months prior to Day 1.

Note: Subjects will have received their MS treatment as monotherapy for the required duration, except during treatment of relapses.

5.2.6.2. Exclusion Criteria

Unless otherwise specified, candidates will be excluded from study entry if any of the following exclusion criteria exist at Screening and on Day 1 or at the timepoint specified in the individual eligibility criterion:

Medical History

-   -   1. Clinical relapse requiring treatment within 30 days prior to         Day 1.     -   2. Pneumococcal vaccination within 5 years prior to Screening.     -   3. Previous exposure to meningococcal vaccines.     -   4. Known hypersensitivity to Td, PPSV23, or MCV4 or their         components.     -   5. History of hepatitis C or hepatitis B virus.     -   6. History of human immunodeficiency virus.     -   7. History of drug or alcohol abuse (as defined by the         Investigator) within 2 years prior to Screening.     -   8. Current smoker or smoking within 6 months prior to Screening.     -   9. Any clinically significant infectious illness (e.g.,         cellulitis, abscess, pneumonia, septicemia) within 30 days prior         to Screening.     -   10. Any active bacterial or viral infection or an oral         temperature ≥38.0° C./100.4° F. on Day 1 or within 3 days prior         to Day 1. Subjects with a clinically significant active         infection or measured oral (sublingual) temperature ≥38.0°         C./100.4° F. should have vaccinations postponed until the         subject's temperature remains below 38.0° C./100.4° F. for at         least 3 days and the subject's acute illness has resolved.     -   11. History of clinically significant cardiovascular,         dermatologic, endocrinologic, gastrointestinal, hematologic,         hepatic, immunologic, metabolic, neurologic (other than MS),         psychiatric, pulmonary, renal, urologic, and/or other major         disease that may confound safety or efficacy assessments.     -   12. History of malignancy (subjects with basal cell carcinoma         that has been completely excised prior to study entry remain         eligible).     -   13. History of severe allergic reactions, anaphylactic         reactions, or known drug hypersensitivity to Tecfidera or         fumaric acid esters.     -   14. Any abnormal laboratory assessment judged to be clinically         significant by the Investigator at Screening.

Note: The following analytes are strictly exclusionary:

-   -   leukocytes <2500/mm³     -   lymphocytes <500/mm³     -   alanine transaminase or aspartate transaminase >2 times the         upper limit of normal

Treatment History

-   -   15. Any type of vaccine, with the exception of inactivated         influenza vaccination (the flu shot), within 4 weeks prior to         Day 1 (the inactivated flu shot is allowed; the intranasal live         vaccine is not allowed).     -   16. Prior treatment with any of the following:         -   cladribine         -   mitoxantrone         -   fingolimod         -   total lymphoid irradiation         -   T-cell or T-cell-receptor vaccination         -   any therapeutic monoclonal antibody, with the exception of             Tysabri® (natalizumab) (see exclusion #17).     -   17. Prior treatment with Tysabri (natalizumab) within 1 year         prior to Screening.     -   18. Prior treatment with any of the following medications or         procedures within 6 months prior to Screening:         -   cyclosporine         -   azathioprine         -   methotrexate         -   mycophenolate mofetil         -   intravenous immunoglobulin         -   plasmapheresis or cytapheresis         -   subcutaneous or oral glatiramer acetate     -   19. Treatment with any immunosuppressive drug or regimen within         3 months prior to Day 1, including but not limited to chronic         steroid use (defined as continuous [>14 days] use of intravenous         or oral corticosteroid treatment, with a dosage equivalence         of >20 mg/day of oral prednisone) or agents that may act through         the corticosteroid pathway (e.g., low dose naltrexone).     -   20. Treatment with any investigational drug or approved therapy         for investigational use within the 6 months prior to Day 1 or         during the study.

Miscellaneous

-   -   21. Female subjects who are currently pregnant or breast-feeding         or planning to become pregnant while in the study.     -   22. Current enrollment in any other investigational study within         6 months prior to Day 1.         -   Note: Current enrollment in an observational study that does             not involve drugs, vaccines, or medical devices is allowed.     -   23. Unwillingness or inability to comply with the requirements         of the protocol including the presence of any condition         (physical, mental, or social) that is likely to affect the         subject's ability to comply with the protocol.     -   24. Any other reasons that, in the opinion of the Investigator         and/or the Sponsor, the subject is determined to be unsuitable         for enrollment in this study.

5.2.7 Treatment of Subjects 5.2.7.1. Vaccinations

On Day 1, following all other assessments, subjects in both groups will receive the following vaccinations intramuscularly in the specified order:

-   -   1. Td (Tenivac®, 0.5 mL)     -   2. PPSV23 (Pneumovax® 23, 0.5 mL)     -   3. MCV4 (Menveo®, 0.5 mL)

5.2.7.2. Concomitant Therapy

A concomitant therapy is any drug or substance administered from the time the subject is enrolled in the study until the subject's final study visit.

5.2.7.3. Disallowed Concomitant Therapy

Concomitant therapy with any of the following is not allowed, unless approved by the Medical Monitor, or as otherwise described in this protocol:

-   -   Any treatment for MS, such as chronic immunosuppressant therapy         or other immunomodulatory treatments (including, but not limited         to: glatiramer acetate, natalizumab, cyclophosphamide,         methotrexate, azathioprine, fingolimod, alemtuzumab,         teriflunomide, or related products, etc.), with the exception of         treatments required as a condition for study eligibility and         treatments for acute management of relapses.     -   Any investigational product, including investigational         symptomatic therapies for MS and investigational therapies or         vaccines for non-MS indications.     -   Any systemic steroid therapy including, but not limited to, oral         corticosteroids (e.g., prednisone) or periodic (e.g., monthly)         treatment with intravenous methylprednisolone, except for         treatment of a relapse. Steroids that are administered by         nonsystemic routes (e.g., topical, inhaled) are allowed.     -   Total lymphoid irradiation, cladribine, T-cell or         T-cell-receptor vaccination, any therapeutic monoclonal         antibody, mitoxantrone, cyclosporine, intravenous         immunoglobulin, plasmapheresis, or cytapheresis.     -   Live or live-attenuated vaccines.

Subjects should be instructed not to start taking any new medications, including nonprescribed drugs, unless they have received permission from the Investigator.

5.2.7.4. Concomitant Procedures

A concomitant procedure is any therapeutic intervention (e.g., surgery/biopsy, physical therapy) or diagnostic assessment (e.g., blood gas measurement, bacterial cultures) performed between the time the subject is enrolled in the study until the subject's final study visit.

The use of concomitant therapies or procedures defined above will be recorded on the subject's case report form (CRF), according to instructions for CRF completion. AEs related to administration of these therapies or procedures will be documented on the appropriate CRF.

5.2.8 Efficacy Assessments

Blood samples will be collected for anti-tetanus, anti pneumococcal, anti meningococcal, and anti-diphtheria IgG titers before vaccination on Day 1 and after vaccination at Week 4 or the Early Withdrawal Visit.

Refer to Table 3: Schedule of Events, for the timing of assessments.

5.2.9 Safety Assessments 5.2.9.1. Clinical Safety Assessments

The following clinical assessments will be performed during the study:

-   -   Vital sign measurements     -   Physical examination     -   Monitoring/recording of AEs     -   Monitoring/recording of concomitant therapy and procedures

Refer to Table 3: Schedule of Events, for the timing of assessments.

5.2.9.2. Laboratory Safety Assessments

The following laboratory tests will be performed during the study:

-   -   Hematology: hemoglobin, hematocrit, red blood cell count, white         blood cell count (with differential), and platelet count     -   Blood chemistry: sodium, potassium, chloride, total bilirubin,         alanine transaminase, aspartate transaminase, gamma glutamyl         transferase, blood urea nitrogen, and creatinine     -   Urine and serum pregnancy tests

Refer to Table 3: Schedule of Events, for the timing of assessments.

5.2.10 References for Example 2

-   Olberg H K, Cox R J, Nostbakken J K, et al. Immunotherapies     influence the influenza vaccination response in multiple sclerosis     patients: an explorative study. Mult Scler. 2014; 20(8):1074-1080. -   Polman C H, Reingold S C, Banwell B, et al. Diagnostic criteria for     multiple sclerosis: 2010 Revisions to the McDonald criteria. Ann     Neurol. 2011; 69(2):292-302. -   Schwid S R, Thorpe J, Sharief M, et al. Enhanced benefit of     increasing interferon beta-1a dose and frequency in relapsing     multiple sclerosis: the EVIDENCE Study. Arch Neurol. 2005;     62(5):785-92.

6. INCORPORATION BY REFERENCE

Various references such as patents, patent applications, and publications are cited herein, the disclosures of which are hereby incorporated by reference herein in their entireties. 

What is claimed is:
 1. A method of treating or preventing multiple sclerosis in a subject in need thereof, comprising (a) administering to the subject a first dose of a pharmaceutical composition for a first dosing period, wherein the pharmaceutical composition comprises a fumarate agent selected from the group consisting of monomethyl fumarate, a compound that metabolizes into monomethyl fumarate in vivo, a deuterated analog thereof, a pharmaceutically acceptable salt thereof, and a combination thereof; (b) administering a vaccine to the subject; and (c) administering to the subject a second dose of the pharmaceutical composition for a second dosing period, wherein the second dosing period is after the first dosing period.
 2. The method of claim 1, wherein the fumarate agent is monomethyl fumarate, dimethyl fumarate, or a combination thereof.
 3. The method of claims 1 or 2, wherein the fumarate agent is dimethyl fumarate.
 4. The method of claim 3, wherein the first dose is a daily amount of about 480 mg dimethyl fumarate.
 5. The method of any of claims 1-4, wherein the second dose is lower than the first dose.
 6. The method of any of claims 1-5, wherein the second dose is 0 mg fumarate agent.
 7. The method of any of claims 1-6, further comprising administering a titration dose of the pharmaceutical composition prior to the first dosing period.
 8. The method of claim 7, wherein the fumarate agent is dimethyl fumarate and the titration dose is a daily amount of about 240 mg dimethyl fumarate.
 9. The method of any of claims 1-8, wherein the first and second doses of the fumarate agent are in a form of microtablets, micropellets, granules, capsules, or tablets.
 10. The method of any of claims 1-9, wherein the dimethyl fumarate is in a form of microtablets, and wherein the microtablets are enterically coated.
 11. The method of any of claims 1-10, wherein the step of administering the vaccine occurs before or during the first dosing period.
 12. The method of any of claims 1-11, wherein the vaccine induces a T cell-dependent immune response.
 13. The method of claim 12, wherein the vaccine induces a T cell-dependent anamnestic humoral immune response.
 14. The method of claim 12, wherein the vaccine induces a T cell-dependent neoantigen immune response.
 15. The method of any of claims 1-11, wherein the vaccine induces a T cell-independent immune response.
 16. The method of any of claims 1-15, wherein serum antibody level induced by the vaccine in the subject is lower compared to average serum antibody level observed in subjects administered with the vaccine but not the fumarate agent, and the second dose is less than the first dose.
 17. The method of any of claims 1-15, wherein serum antibody level induced by the vaccine in the subject increases less than 4-fold from pre-vaccination to 4 weeks after vaccination, and the second dose is less than the first dose.
 18. The method of any of claims 1-17, wherein the vaccine is a live or inactive vaccine.
 19. The method of claim 18, wherein the vaccine is an inactive vaccine.
 20. The method of any of claims 1-17, wherein the vaccine is a vaccine selected from the group consisting of tetanus diphtheria toxoids vaccine, keyhole limpet hemocyanin vaccine, pneumovax-23 vaccine, and any combinations thereof.
 21. The method of any of claims 1-17, wherein the vaccine is tetanus diphtheria toxoids vaccine.
 22. The method of any of claims 1-17, wherein the vaccine is keyhole limpet hemocyanin vaccine.
 23. The method of claims 1-17, wherein the vaccine is pneumovax-23 vaccine.
 24. The method of any of claims 1-23, wherein the second dose is 0 mg fumarate agent.
 25. A method of treating or preventing a neurological disease or disorder in a subject in need thereof, comprising (a) administering to the subject a first dose of a pharmaceutical composition for a first dosing period, wherein the pharmaceutical composition comprises a fumarate agent selected from the group consisting of monomethyl fumarate, a compound that metabolizes into monomethyl fumarate in vivo, a deuterated analog thereof, a pharmaceutically acceptable salt thereof, and a combination thereof, wherein the subject receives a vaccine; (b) determining an immune response of the subject to the vaccine before the end of the first dosing period; and (c) administering to the subject a second dose of the pharmaceutical composition for a second dosing period, wherein the second dose is equal to or less than the first dose.
 26. The method of claim 25, wherein the neurological disease or disorder is multiple sclerosis.
 27. The method of claims 25 or 26, wherein the fumarate agent is monomethyl fumarate, dimethyl fumarate, or a combination thereof.
 28. The method of any of claims 25-27, wherein the fumarate agent is dimethyl fumarate.
 29. The method of claim 28, wherein the first dose is a daily amount of about 480 mg dimethyl fumarate.
 30. The method of any of claims 25-29, wherein the second dose is 0 mg fumarate agent.
 31. The method of any of claims 25-30, further comprising administering a titration dose of the pharmaceutical composition prior to the first dosing period.
 32. The method of claim 31, wherein the fumarate agent is dimethyl fumarate and the titration dose is a daily amount of about 240 mg dimethyl fumarate.
 33. The method of any of claims 25-32, wherein the first and second doses of the fumarate agent are in a form of microtablets, micropellets, granules, capsules, or tablets.
 34. The method of any of claims 25-33, wherein the dimethyl fumarate is in a form of microtablets, and wherein the microtablets are enterically coated.
 35. The method of any of claims 25-34, wherein the subject receives the vaccine about 2 to 4 weeks before the start of the first dosing period, or during the first dosing period.
 36. The method of any of claims 25-35, wherein the subject receives the second dose of the fumarate agent following the end of the first dosing period.
 37. The method of any of claims 25-36, wherein the vaccine induces a T-cell dependent immune response.
 38. The method of any of claims 25-37, wherein the vaccine induces a T-cell independent immune response.
 39. The method of any of claims 25-38, wherein the immune response of the subject to the vaccine is characterized in that the serum antibody level induced by the vaccine in the subject increases less than 4-fold from pre-vaccination to 4 weeks after vaccination, and the second dose is less than the first dose.
 40. The method of any of claims 25-39, wherein the immune response of the subject to the vaccine is characterized in that the serum antibody level induced by the vaccine in the subject increases at least 2-fold from pre-vaccination to 4 weeks after vaccination, wherein the second dose is the same as the first dose.
 41. The method of any of claims 25-40, wherein the immune response of the subject to the vaccine is characterized in that the serum antibody level induced by the vaccine in the subject is lower compared to average serum antibody level induced by the vaccine in subjects administered with the vaccine but no fumarate agent, and the second dose is less than the first dose.
 42. The method of any of claims 25-41, wherein the vaccine is a live or inactive vaccine.
 43. The method of claim 42, wherein the vaccine is an inactive vaccine.
 44. The method of any of claims 25-41, wherein the vaccine is a vaccine selected from the group consisting of tetanus diphtheria toxoids vaccine, keyhole limpet hemocyanin vaccine, pneumovax-23 vaccine, and any combinations thereof.
 45. The method of any of claims 25-41, wherein the vaccine is tetanus diphtheria toxoids vaccine.
 46. The method of any of claims 25-41, wherein the vaccine is keyhole limpet hemocyanin vaccine.
 47. The method of claims 25-41, wherein the vaccine is pneumovax-23 vaccine.
 48. A method of treating or preventing a neurological disease or disorder in a subject who receives a vaccine, comprising: (a) screening a plurality of doses of a pharmaceutical composition comprising a fumarate agent selected from the group consisting of monomethyl fumarate, a compound that metabolizes into monomethyl fumarate in vivo, a deuterated analog thereof, a pharmaceutically acceptable salt thereof, and a combination thereof, by (1) identifying a first group of subjects and at least a second group of subjects, wherein both the first and second groups of subjects receive the vaccine while treated with the fumarate agent, wherein the first group of subjects is treated with a first dose of the fumarate agent, and the second group of subjects is treated with a second dose of the fumarate agent; (2) determining a lower risk dose; and (b) administering the lower risk dose of the pharmaceutical composition to the subject.
 49. The method of claim 48, wherein the neurological disease or disorder is multiple sclerosis.
 50. The method of claims 48 or 49, wherein the fumarate agent is dimethyl fumarate.
 51. The method of claim 50, wherein the first dose is a daily amount of about 480 mg dimethyl fumarate.
 52. The method of any of claims 48-51, wherein the second dose is 0 mg fumarate agent.
 53. The method of any of claims 48-52, further comprising administering a titration dose of the pharmaceutical composition to the subject.
 54. The method of any of claims 48-53, wherein the fumarate agent is dimethyl fumarate and the titration dose is a daily amount of about 240 mg dimethyl fumarate.
 55. The method of claims 48-54, wherein the group of subjects treated with the lower risk dose have higher proportion of subjects with at least 2-fold increase in serum antibody levels induced by the vaccine from pre-vaccination to 4 weeks after vaccination.
 56. The method of claims 48-54, wherein the group of subjects treated with the lower risk dose have higher proportion of subjects having serum antibody levels induced by the vaccine not less than average serum antibody level observed in subjects administered with the vaccine but no fumarate agent at 4 weeks after vaccination.
 57. The method of any of claims 48-56, wherein the vaccine is a live or inactive vaccine.
 58. The method of claim 57, wherein the vaccine is an inactive vaccine.
 59. The method of any of claims 48-56, wherein the vaccine is a vaccine selected from the group consisting of tetanus diphtheria toxoids vaccine, keyhole limpet hemocyanin vaccine, pneumovax-23 vaccine, and any combinations thereof.
 60. The method of any of claims 48-56, wherein the vaccine is tetanus diphtheria toxoids vaccine.
 61. The method of any of claims 48-56, wherein the vaccine is keyhole limpet hemocyanin vaccine.
 62. The method of claims 48-56, wherein the vaccine is pneumovax-23 vaccine.
 63. The method of any of claims 48-62, wherein the lower risk dose is the second dose, wherein the second dose is less than the first dose.
 64. A method of treating or preventing multiple sclerosis in a subject in need thereof, comprising (a) determining a subject's baseline lymphocyte count prior to treatment; (b) administering to the subject a first dose of a pharmaceutical composition for a first dosing period, wherein the pharmaceutical composition comprises a fumarate agent selected from the group consisting of monomethyl fumarate, a compound that metabolizes into monomethyl fumarate in vivo, a deuterated analog thereof, a pharmaceutically acceptable salt thereof, and a combination thereof; (c) determining a subject's total lymphocyte count after the first dosing period; and (d) if the lymphocyte count after the first dosing period is about 90% of the baseline lymphocyte count or lower, do not administer tetanus diphtheria toxoids vaccine, keyhole limpet hemocyanin vaccine, pneumovax-23 vaccine, or any combinations thereof.
 65. The method of claim 64, wherein the subject's lymphocyte count is 70% of the baseline lymphocyte count or lower.
 66. The method of claim 64, wherein the subject's lymphocyte count is 50% of the baseline lymphocyte count or lower.
 67. The method of any of claims 64-66, wherein the fumarate agent is monomethyl fumarate, dimethyl fumarate, or a combination thereof.
 68. The method of claims 64-66, wherein the fumarate agent is dimethyl fumarate.
 69. The method of claim 67, wherein the first dose is a daily amount of about 480 mg dimethyl fumarate.
 70. The method of any of claims 64-69, further comprising administering to the subject a second dose for a second dosing period.
 71. The method of claim 70, wherein the second dose is lower than the first dose.
 72. The method of claim 71, wherein the second dose is 0 mg fumarate agent.
 73. The method of any of claims 64-72, further comprising administering a titration dose of the pharmaceutical composition prior to the first dosing period.
 74. The method of claim 73, wherein the fumarate agent is dimethyl fumarate and the titration dose is a daily amount of about 240 mg dimethyl fumarate.
 75. The method of any of claims 70-74, wherein the first and second doses of the fumarate agent are in a form of microtablets, micropellets, granules, capsules, or tablets.
 76. The method of any of claims 64-75, wherein the dimethyl fumarate is in a form of microtablets, and wherein the microtablets are enterically coated.
 77. The method of any of claims 64-76, further comprising administering a vaccine, wherein the step of administering the vaccine occurs before or during the first dosing period.
 78. The method of claim 77, wherein the vaccine induces a T cell-dependent immune response.
 79. The method of claim 77, wherein the vaccine induces a T cell-dependent anamnestic humoral immune response.
 80. The method of claim 77, wherein the vaccine induces a T cell-dependent neoantigen immune response.
 81. The method of claim 77, wherein the vaccine induces a T cell-independent immune response.
 82. The method of any of claims 77-81, wherein serum antibody level induced by the vaccine in the subject is lower compared to average serum antibody level observed in subjects administered with the vaccine but not the fumarate agent, and the second dose is less than the first dose.
 83. The method of any of claims 77-81, wherein serum antibody level induced by the vaccine in the subject increases less than 4-fold from pre-vaccination to 4 weeks after vaccination, and the second dose is less than the first dose.
 84. The method of any of claims 77-81, wherein the vaccine is a live or inactive vaccine.
 85. The method of claim 84, wherein the vaccine is an inactive vaccine.
 86. The method of any of claims 77-85, wherein the vaccine is a vaccine selected from the group consisting of tetanus diphtheria toxoids vaccine, keyhole limpet hemocyanin vaccine, pneumovax-23 vaccine, and any combinations thereof.
 87. The method of claim 86, wherein the vaccine is tetanus diphtheria toxoids vaccine.
 88. The method of claim 86, wherein the vaccine is keyhole limpet hemocyanin vaccine.
 89. The method of claim 86, wherein the vaccine is pneumovax-23 vaccine.
 90. The method of any of claims 70-89, wherein the second dose is 0 mg fumarate agent.
 91. A method of treating multiple sclerosis in a human subject in need thereof comprising (a) administering a therapeutically effective amount of dimethyl fumarate to the subject; and (b) administering a vaccine to the subject.
 92. The method of claim 91, wherein the therapeutically effective amount of dimethyl fumarate is a maintenance dose that is repeatedly administered over at least a period of time, and said step (b) of administering said vaccine is during said period of time.
 93. The method of claim 91 or 92, wherein the maintenance dose is orally administered 240 mg dimethyl fumarate twice daily.
 94. The method of any of claims 91-93, wherein the period of time is 1 week.
 95. The method of any of claims 91-93, wherein the period of time is 6 months.
 96. The method of any of claims 91-95, wherein the immune response to said vaccine is decreased in said subject relative to the immune response in the absence of said step (a) of administering a therapeutically effective amount of dimethyl fumarate.
 97. The method of any of claims 91-96, wherein the multiple sclerosis is a relapsing form of multiple sclerosis.
 98. The method of claim 97, wherein the multiple sclerosis is relapsing-remitting multiple sclerosis. 